Difference between revisions of "Anthracene" - New World Encyclopedia
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SMILES=c23cc1ccccc1cc2cccc3}} | SMILES=c23cc1ccccc1cc2cccc3}} | ||
− | In chemistry, '''anthracene''' is a solid [[polycyclic aromatic hydrocarbon]] consisting of three [[benzene]] rings derived from [[coal-tar]]. Anthracene is used in the artificial [[Economic production|production]] of the [[red]] [[dye]] [[alizarin]]. It is also used in [[wood]] [[preservative]]s, [[insecticide]]s, and coating [[commodity|materials]]. | + | In chemistry, '''anthracene''' is a solid [[polycyclic aromatic hydrocarbon]] consisting of three [[benzene]] rings derived from [[coal-tar]]. Anthracene is used in the artificial [[Economic production|production]] of the [[red]] [[dye]] [[alizarin]]. It is also used in [[wood]] [[preservative]]s, [[insecticide]]s, and coating [[commodity|materials]]. Anthracene is colorless but exhibits a blue (400-500nm peak) [[fluorescence]] under [[ultraviolet]] light. |
==Synthesis== | ==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 | + | 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]] (September 13, 1858 – August 24, 1933)). |
==Reactions== | ==Reactions== | ||
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[[Image:anthracene-dimer.png|Anthracene dimer]] | [[Image:anthracene-dimer.png|Anthracene dimer]] | ||
− | 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 | + | 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 are 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.<!-- because the [[pi electron]]s do not equally [[Delocalized electron|delocalize]] across the whole structure? is that the correct way to say why? —> | + | In most other reactions of anthracene, the central ring is also targeted, as it is the most highly reactive.<!-- because the [[pi electron]]s do not equally [[Delocalized electron|delocalize]] across the whole structure? is that the correct way to say why? —> [[Electrophilic substitution]] occurs at the "9" and "10" positions of the center ring, and [[oxidation]] of anthracene occurs readily, giving [[anthraquinone]], C<sub>14</sub>H<sub>8</sub>O<sub>2</sub> (below). |
:[[Image:Anthraquinone.PNG|120px|none|Anthraquione]] | :[[Image:Anthraquinone.PNG|120px|none|Anthraquione]] | ||
==Uses== | ==Uses== | ||
− | Anthracene can also have a [[Hydroxide|hydroxyl group]] to form 1-hydroxyanthracene and 2-hydroxyanthracene, homologous to [[phenol]] and [[napthol]], and hydroxyanthracene is also called anthrol, and anthracenol.<ref>[http://webbook.nist.gov/cgi/cbook.cgi?Name=1-hydroxyanthracene&Units=SI 1-Hydroxyanthracene | + | Anthracene can also have a [[Hydroxide|hydroxyl group]] to form 1-hydroxyanthracene and 2-hydroxyanthracene, homologous to [[phenol]] and [[napthol]], and hydroxyanthracene is also called anthrol, and anthracenol.<ref>[http://webbook.nist.gov/cgi/cbook.cgi?Name=1-hydroxyanthracene&Units=SI 1-Hydroxyanthracene] ''NIST''. Retrieved October 16, 2007.</ref><ref>[http://webbook.nist.gov/cgi/cbook.cgi?Name=2-hydroxyanthracene&Units=SI 2-Hydroxyanthracene] ''NIST''. Retrieved October 16, 2007.</ref> Hydroxyanthracene derivatives are [[pharmacology|pharmacologically]] active, and are contained in [[aloe]], for example.<ref>[http://www.tga.gov.au/docs/html/tganews/news23/chem.htm TGA News Issue 23 (April 1997): Labelling of herbs containing hydroxyanthracene derivatives] ''Therapeutic Goods Administration, Australian Government''. Retrieved October 16, 2007.</ref><ref>[http://www.uspharmacist.com/oldformat.asp?url=newlook/files/comp/acf1e63.htm Herbals and Breastfeeding] ''U.S. Pharmacist''. Retrieved October 16, 2007.</ref> |
Anthracene is an [[organic semiconductor]]. | Anthracene is an [[organic semiconductor]]. | ||
− | Anthracene is used as a [[scintillator]] for detectors of high energy [[photon]]s, [[electron]]s and [[alpha particle]]s. | + | Anthracene is used as a [[scintillator]] for detectors of high energy [[photon]]s, [[electron]]s and [[alpha particle]]s. 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== | ==See also== | ||
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== References == | == References == | ||
− | * McMurry, John. 2004. ''Organic Chemistry''. 6th ed. Belmont, CA: Brooks/Cole. ISBN 0534420052 | + | * McMurry, John. 2004. ''Organic Chemistry''. 6th ed. Belmont, CA: Brooks/Cole. ISBN 0534420052 |
− | + | * Morrison, Robert T., and Robert N. Boyd. 1992. ''Organic Chemistry''. 6th ed. Englewood Cliffs, NJ: Prentice Hall. ISBN 0-13-643669-2 | |
− | * Morrison, Robert T., and Robert N. Boyd. 1992. ''Organic Chemistry''. 6th ed. Englewood Cliffs, NJ: Prentice Hall. ISBN 0-13-643669-2 | + | * Solomons, T.W. Graham, and Fryhle, Craig B. 2004. ''Organic Chemistry''. 8th ed. Hoboken, NJ: John Wiley. ISBN 0471417998 |
− | |||
− | * Solomons, T.W. Graham, and Fryhle, Craig B. 2004. ''Organic Chemistry''. 8th ed. Hoboken, NJ: John Wiley. ISBN 0471417998 | ||
==External links== | ==External links== | ||
− | *{{ICSC|0825|08}} | + | *{{ICSC|0825|08}} Retrieved October 16, 2007. |
− | + | * [http://www.npi.gov.au/database/substance-info/profiles/74.html National Pollutant Inventory - Polycyclic Aromatic Hydrocarbon Fact Sheet] Retrieved October 16, 2007. | |
− | * [http://www.npi.gov.au/database/substance-info/profiles/74.html National Pollutant Inventory - Polycyclic Aromatic Hydrocarbon Fact Sheet] | + | *[http://webbook.nist.gov/cgi/cbook.cgi?Name=anthracene&Units=SI NIST Chemistry WebBook Anthracene] Retrieved October 16, 2007. |
− | *[http://webbook.nist.gov/cgi/cbook.cgi?Name=anthracene&Units=SI NIST Chemistry WebBook Anthracene] | ||
[[Category:Physical sciences]] | [[Category:Physical sciences]] |
Revision as of 03:04, 17 October 2007
Anthracene | |
---|---|
IUPAC name | Anthracene |
Molecular formula | C14H10 |
Molar mass | 178.23 g/mol |
CAS number | [ | ]
Density | 1.099 g/cm³ |
Melting point |
217.5 °C |
Boiling point |
340 °C |
SMILES | c23cc1ccccc1cc2cccc3 |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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.
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 (September 13, 1858 – August 24, 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 are 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).
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
- Benzene
- Phenanthrene
- Tetracene
Notes
- ↑ 1-Hydroxyanthracene NIST. Retrieved October 16, 2007.
- ↑ 2-Hydroxyanthracene NIST. Retrieved October 16, 2007.
- ↑ TGA News Issue 23 (April 1997): Labelling of herbs containing hydroxyanthracene derivatives Therapeutic Goods Administration, Australian Government. Retrieved October 16, 2007.
- ↑ Herbals and Breastfeeding U.S. Pharmacist. Retrieved October 16, 2007.
ReferencesISBN links support NWE through referral fees
- McMurry, John. 2004. Organic Chemistry. 6th ed. Belmont, CA: Brooks/Cole. ISBN 0534420052
- Morrison, Robert T., and Robert N. Boyd. 1992. Organic Chemistry. 6th ed. Englewood Cliffs, NJ: Prentice Hall. ISBN 0-13-643669-2
- Solomons, T.W. Graham, and Fryhle, Craig B. 2004. Organic Chemistry. 8th ed. Hoboken, NJ: John Wiley. ISBN 0471417998
External links
- International Chemical Safety Card 0825 – International Occupational Safety and Health Information Centre, International Labour Organization. Retrieved October 16, 2007.
- National Pollutant Inventory - Polycyclic Aromatic Hydrocarbon Fact Sheet Retrieved October 16, 2007.
- NIST Chemistry WebBook Anthracene Retrieved October 16, 2007.
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