Indene
![Ball-and-stick model of the indene molecule](/Images/godic/202501/20/Indene_3D_ball5150.png")
Indene is a flammable polycyclic hydrocarbon with chemical formula C9H8. It is composed of a benzene ring fused with a cyclopentene ring. This aromatic liquid is colorless although samples often are pale yellow. The principal industrial use of indene is in the production of indene/coumarone thermoplastic resins.