9-Methylene-fluorene or dibenzofulvene (DBF) is a polycyclic aromatic hydrocarbon with chemical formula (C6H4)2C=CH2.

It is best known as one product from deprotection of the Fmoc group.

[1] It can be prepared by treatment of 9-hydroxymethylfluorene with strong base.

Polymerization of 9-methylene-fluorene produces a π-stacked polymer.

[3] This article about a hydrocarbon is a stub.