Fulvene

Fulvene (pentafulvene) is a hydrocarbon with the formula (CH=CH)2C=CH2. It is a prototype of a cross-conjugated hydrocarbon. Fulvene is rarely encountered, but substituted derivatives (fulvenes) are numerous. They are mainly of interest as ligands and precursors to ligands in organometallic chemistry.

Fulvene is an isomer of benzene, which when irradiated at 237 to 254 nm forms small amounts of fulvene along with benzvalene.