Fluorene

Fluorene

Names
Preferred IUPAC name 9H-Fluorene
Systematic IUPAC name Tricyclo[7.4.0.02,7]trideca-2,4,6,9,11,13-hexaene
Identifiers
CAS Number	86-73-7 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:28266 Y
ChEMBL	ChEMBL16236 Y
ChemSpider	6592 Y
ECHA InfoCard	100.001.541
EC Number	201-695-5
KEGG	C07715 Y
PubChem	6853
RTECS number	LL5670000
UNII	3Q2UY0968A Y
InChI InChI=1S/C13H10/c1-3-7-12-10(5-1)9-11-6-2-4-8-13(11)12/h1-8H,9H2 Y Key: NIHNNTQXNPWCJQ-UHFFFAOYSA-N Y InChI=1/C13H10/c1-3-7-12-10(5-1)9-11-6-2-4-8-13(11)12/h1-8H,9H2 Key: NIHNNTQXNPWCJQ-UHFFFAOYAW
SMILES c1ccc2c3ccccc3Cc2c1
Properties
Chemical formula	C13H10
Molar mass	166.22 g·mol−1
Density	1.202 g/mL
Melting point	116 to 117 °C (241 to 243 °F; 389 to 390 K)
Boiling point	295 °C (563 °F; 568 K)
Solubility in water	1.992 mg/L
Solubility	soluble in CS2, ether, benzene, hot alcohol, pyrimidine, CCl4, toluene, acetone, DMSO
log P	4.18
Acidity (pKa)	22.6
Magnetic susceptibility (χ)	-110.5·10−6 cm3/mol
Hazards
Safety data sheet	Sigma-Aldrich
NFPA 704	1 1 0
Flash point	152 °C (306 °F; 425 K)
Lethal dose or concentration (LD, LC):
LD50 (median dose)	16000 mg/kg (oral, rat)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Fluorene /ˈflʊəriːn/, 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, hence its name. For commercial purposes it is obtained from coal tar. It is insoluble in water and soluble in many organic solvents.

Although fluorene is obtained from coal tar, it can also be prepared by dehydrogenation of diphenylmethane. Alternatively, it can be prepared by the reduction of fluorenone with zinc. The fluorene molecule is nearly planar, although each of the two benzene rings is coplanar with the central carbon 9.

The C9-H sites of the fluorene ring are weakly acidic (pK_a = 22.6 in DMSO.) Deprotonation gives the stable fluorenyl "anion", nominally C₁₃H₉⁻, 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. The purification of fluorene exploits its acidity and the low solubility of its sodium derivative in hydrocarbon solvents.

Both protons can be removed from C9. For example, 9,9-fluorenyldipotassium can be obtained by treating fluorene with potassium metal in boiling dioxane.

Fluorene is a precursor to other fluorene compounds; the parent species has few applications. Fluorene-9-carboxylic acid is a precursor to pharmaceuticals. 2-Aminofluorene, 3,6-bis-(dimethylamino)fluorene, and 2,7-diiodofluorene are precursors to dyes. Oxidation of fluorene gives fluorenone, which is nitrated to give commercially useful derivatives. 9-Fluorenylmethyl chloroformate (Fmoc chloride) is used to introduce the 9-fluorenylmethyl carbamate (Fmoc) protecting group on amines in peptide synthesis.