ANTHRACENE

Anthracene
Anthracene Anthracene 3D
General
Systematic name	Anthracene
Molecular formula	C14H10
SMILES	C12=CC=CC=C1C=C3C(C=CC=C3)=C2
InChI	InChI=1/C14H10/c1-2- 6-12-10-14-8-4-3-7- 13(14)9-11(12)5-1/ h1-10H
Molar mass	178.23 g/mol
Appearance	Light Brown
CAS number	[120-12-7]
Properties
Density and phase	1.25 g/cm³ at 19.85°C, Solid 0.969 g/cm³ at 220°C, liquid
Melting point	218°C
Sublimation Temperature	129.85 at 759.811 Torr
Boiling point	340°C
Crystal System	Monoclinic
Solubility	Water: none Methanol: 0.908g per liter Hexane: 1.64g per liter
Hazards
Main hazards	Irritant Dangerous for the Environment
Autoignition Temperature	1004°C

In chemistry, 'anthracene' is a solid polycyclic aromatic hydrocarbon consisting of three benzene rings derived from coal-tar. Anthracene is used in the artificial production of the red dye alizarin. It is also used in wood preservatives, insecticides, and coating materials. Anthracene is colorless but exhibits a blue (400-500nm peak) fluorescence under ultraviolet light.

Contents

Synthesis

Reactions

Uses

See also

External links

Synthesis

A classic method for the preparation of anthracene in the laboratory is by cyclodehydration of o-methyl- or o-methylene-substituted diarylketones in the so-called 'Elbs reaction' (named for the German chemist Karl Elbs, born 13 September 1858 in Alt-Breisach, Baden, Germany, died 24 August 1933).

Reactions

Anthracene has the ability to photodimerize with irradiation by UV light. This results in considerable changes in the physical properties of the material.

The dimer is connected by two covalent bonds resulting from the [4+4] cycloaddition. The dimer reverts to anthracene thermally or with UV irradiation below 300 nm. The reversible bonding and photochromic properties of anthracenes is the basis of many potential applications using poly and monosubstituted anthracene derivatives. The reaction is sensitive to oxygen.
In most other reactions of anthracene, the central ring is also targeted, as it is the most highly reactive. Electrophilic substitution occurs at the "9" and "10" positions of the center ring, and oxidation of anthracene occurs readily, giving anthraquinone, C₁₄H₈O₂ (below).
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Uses

Anthracene can also have a hydroxyl group to form 1-hydroxyanthracene and 2-hydroxyanthracene, homologous to phenol and napthol, and hydroxyanthracene is also called anthrol, and anthracenol.[1][2]
Hydroxyanthracene derivatives are pharmacologically active, and are contained in aloe for example.[3][4]
Anthracene is an organic semiconductor.
Anthracene is used as a scintillator for detectors of high energy photons, electrons and alpha particles. Plastics such as polyvinyltolulene can be doped with Anthracene to produce a plastic scintillator that is approximately water equivalent for use in radiation therapy dosimetry. Anthracenes emission spectrum peaks at between 400nm and 440nm.

See also

★ Phenanthrene

★ Tetracene

External links

★

★ IARC Monograph "Anthracene."

★ National Pollutant Inventory - Polycyclic Aromatic Hydrocarbon Fact Sheet

★ NIST Chemistry WebBook Anthracene