9halofluorene

9H-fluorene, often referred to as fluorene, is an organic compound with the chemical formula C13H10. It is a polycyclic aromatic hydrocarbon consisting of two benzene rings fused to a central five-membered ring. This structure gives fluorene a planar geometry. Pure fluorene is a white crystalline solid that is insoluble in water but soluble in many organic solvents like ethanol and ether.

Fluorene occurs naturally in coal tar, from which it can be isolated. It is also a component of cigarette smoke. The compound's reactivity is primarily associated with the methylene group at the 9-position of the five-membered ring, which is relatively acidic due to resonance stabilization of the resulting carbanion. This allows for various chemical modifications and the synthesis of fluorene derivatives.

Fluorene and its derivatives find applications in organic electronics, such as in the development of organic light-emitting diodes (OLEDs) and organic solar cells. Its rigid, planar structure and conjugated pi-electron system contribute to favorable electronic and optical properties. Furthermore, fluorene-based compounds are used as monomers in the synthesis of polymers with unique characteristics, and in some pharmaceutical research.