ferrocene

noun Chemistry.

1. Also called dicyclopentadienyliron. an orange, crystalline, water-insoluble coordination compound, (C5H5)2Fe, having a camphorlike odor: used chiefly as an antiknock agent for gasoline and as a catalyst.Compare metallocene.
2. Also called dicyclopentadienyl metal. any of a class of analogous compounds containing a metal other than iron, as nickel or osmium.

noun

1. a reddish-orange insoluble crystalline compound. Its molecules have an iron atom sandwiched between two cyclopentadiene rings. Formula: Fe(C 5 H 5) 2