Fluorene

Fluorene

Identifiers
CAS Number	86-73-7
3D model (JSmol)	Interactive image
ECHA InfoCard	100.001.541
EC Number	201-695-5
CompTox Dashboard (EPA)	DTXSID8024105
SMILES C12=CC=CC=C1C(C=CC=C3)=C3C2
Properties
Chemical formula	C13H10
Molar mass	166.223 g/mol
Density	1.202 g/mL
Melting point	116-117 °C
Boiling point	295 °C
Acidity (pKa)	23
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Not be confused with fluorone, or the element fluorine.

Fluorene, or 9H-fluorene, is a polycyclic aromatic hydrocarbon. It forms white crystals that exhibit a characteristic, aromatic odor similar to that of naphthalene. It is combustible. It has a violet fluorescence, which gave it its name. It is manufactured artificially, although it occurs in the higher boiling fractions of coal tar. It is insoluble in water and soluble in benzene and ether.

Fluorene is used to make dyes, plastics, and pesticides. It can be found in corn silk and engine exhaust gas. It is used for production of fluorenone and fluorene-9-methanol.

Poly(fluorene) is commonly used as a luminophore in organic light-emitting diodes. Fluorene copolymers are being investigated as materials for solar cells.

The protons in the 9-position of the fluorene ring are acidic (pK_a = 22.6 in DMSO) and removal of one of them with a base, such as sodium hydroxide, leads to the stable fluorenyl anion, which is aromatic and has an intense orange colour. The anion is a nucleophile and most electrophiles react with it by adding to the 9-position. For example, fluorenol, the alcohol of fluorene, is created when a hydroxyl group is placed in the 9-position.

9-Fluorenylmethyl chloroformate (Fmoc chloride) is used to introduce the 9-fluorenylmethyl carbamate (Fmoc) protecting group on amines in peptide synthesis.

External links

• National Pollutant Inventory - Polycyclic Aromatic Hydrocarbon Fact Sheet
• Fluorene in the National Institute of Standards and Technology database.