Anthracene

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Anthracene
Skeletal formula and numbering system of anthracene
Ball-and-stick model of the anthracene molecule
Anthracene
Names
Preferred IUPAC name
Anthracene
Systematic IUPAC name
Tricyclo[8.4.0.03,8]tetradeca-1,3,5,7,9,11,13-heptaene
Identifiers
CAS Number
3D model (JSmol)
1905429
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.003.974 Edit this at Wikidata
EC Number
  • 217-004-5
Gmelin Reference
 67837
KEGG
PubChem CID
RTECS number
  • CA9350000
UNII
CompTox Dashboard (EPA)
InChI
Properties
Chemical formula
 C14H10
Molar mass 178.234 g·mol−1
Appearance Colorless
Odor Weak aromatic
Density 1.28 g/cm3 (25 °C)[1]
0.969 g/cm3 (220 °C)
Melting point 216 °C (421 °F; 489 K)[1] at 760 mmHg
Boiling point 341.3 °C (646.3 °F; 614.5 K)[1] at 760 mmHg
Solubility in water
 0.022 mg/L (0 °C)
0.044 mg/L (25 °C)
0.29 mg/L (50 °C)
0.00045% w/w (100 °C, 3.9 MPa)[2]
Solubility Soluble in alcohol, (C2H5)2O, acetone, C6H6, CHCl3,[1] CS2[3]
Solubility in ethanol 0.76 g/kg (16 °C)
1.9 g/kg (19.5 °C)
3.28 g/kg (25 °C)[3]
Solubility in methanol 18 g/kg (19.5 °C)[3]
Solubility in hexane 3.7 g/kg[3]
Solubility in toluene 9.2 g/kg (16.5 °C)
129.4 g/kg (100 °C)[3]
Solubility in carbon tetrachloride 7.32 g/kg[3]
log P 4.56
Vapor pressure 0.01 kPa (125.9 °C)
0.1 kPa (151.5 °C)[4]
13.4 kPa (250 °C)[5]
0.0396 L·atm/mol[6]
UV-vis (λmax) 345.6 nm, 363.2 nm[5]
Magnetic susceptibility (χ)
 −129.8×10−6 cm3/mol[7]
Thermal conductivity 0.1416 W/(m·K) (240 °C)
0.1334 W/(m·K) (270 °C)
0.1259 W/(m·K) (300 °C)[8]
Viscosity 0.602 cP (240 °C)
0.498 cP (270 °C)
0.429 cP (300 °C)[8]
Structure
Crystal structure
 Monoclinic (290 K)[9]
Space group
 P21/b[9]
Point group
 D5
2h[9]
Lattice constant
a = 8.562 Å, b = 6.038 Å, c = 11.184 Å[9]
α = 90°, β = 124.7°, γ = 90°
Thermochemistry[10]
Heat capacity (C)
 210.5 J/(mol·K)
Std molar
entropy (So298)
 207.5 J/(mol·K)
Std enthalpy of
formation (ΔfH⦵298)
 129.2 kJ/mol
Std enthalpy of
combustion (ΔcH⦵298)
 7061 kJ/mol[5]
Hazards
GHS pictograms GHS07: HarmfulGHS09: Environmental hazard[11]
GHS Signal word Warning
GHS hazard statements
 H302, H305, H315, H319, H335, H410[11]
GHS precautionary statements
 P261, P273, P305+351+338, P501[11]
NFPA 704 (fire diamond)
1
1
0
Flash point 121 °C (250 °F; 394 K)[11]
Autoignition
temperature
 540 °C (1,004 °F; 813 K)[11]
Lethal dose or concentration (LD, LC):
LD50 (median dose)
 100-149 mg/kg (rats, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Fluorescence of Anthracene under UV light

Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Anthracene is used in the production of the red dye alizarin and other dyes. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation.[13]

Occurrence and production[]

Coal tar, which contains around 1.5% anthracene, remains a major source of this material. Common impurities are phenanthrene and carbazole. The mineral form of anthracene is called freitalite and is related to a coal deposit.[14] A classic laboratory method for the preparation of anthracene is by cyclodehydration of o-methyl- or o-methylene-substituted diarylketones in the so-called Elbs reaction.

Reactions[]

Reduction[]

Reduction of anthracene with alkali metals yields the deeply colored radical anion salts M+[anthracene]− (M = Li, Na, K). Hydrogenation gives 9,10-dihydroanthracene, preserving the aromaticity of the two flanking rings.[15]

Cycloadditions[]

Anthracene photodimerizes by the action of UV light:

Anthracene dimer

The dimer, called dianthracene (or sometimes paranthracene), is connected by a pair of new carbon-carbon bonds, the result of the [4+4] cycloaddition. It reverts to anthracene thermally or with UV irradiation below 300 nm. Substituted anthracene derivatives behave similarly. The reaction is affected by the presence of oxygen.[16][17]

Anthracene also reacts with dienophile singlet oxygen in a [4+2]-cycloaddition (Diels–Alder reaction):

Diels alder reaction of anthracene with singlet oxygen

With electrophiles[]

Chemical oxidation occurs readily, giving anthraquinone, C14H8O2 (below), for example using hydrogen peroxide and vanadyl acetylacetonate.[18]

Anthraquione

Electrophilic substitution of anthracene occurs at the 9 position. For example, formylation affords 9-anthracenecarboxaldehyde. Substitution at other positions is effected indirectly, for example starting with anthroquinone.[19] Bromination of anthracene gives 9,10-dibromoanthracene.[20]

Uses[]

Anthracene is converted mainly to anthraquinone, a precursor to dyes.[21]

Niche[]

Anthracene, a wide band-gap organic semiconductor is used as a scintillator for detectors of high energy photons, electrons and alpha particles. Plastics, such as polyvinyltoluene, can be doped with anthracene to produce a plastic scintillator that is approximately water-equivalent for use in radiation therapy dosimetry. Anthracene's emission spectrum peaks at between 400 nm and 440 nm.

It is also used in wood preservatives, insecticides, and coating materials.[citation needed]

Anthracene is commonly used as a UV tracer in conformal coatings applied to printed wiring boards. The anthracene tracer allows the conformal coating to be inspected under UV light.[22] Anthracene also used in manufacturing of anthraquinone.

Derivatives[]

False-color AFM image of anthracene diradical, where hydrogen atoms are removed at carbons 9 and 10

A variety of anthracene derivatives find specialized uses. Derivatives having a hydroxyl group are 1-hydroxyanthracene and 2-hydroxyanthracene, homologous to phenol and naphthols, and hydroxyanthracene (also called anthrol, and anthracenol)[23][24] are pharmacologically active. Anthracene may also be found with multiple hydroxyl groups, as in 9,10-dihydroxyanthracene.

Occurrence[]

Anthracene, as many other polycyclic aromatic hydrocarbons, is generated during combustion processes. Exposure to humans happens mainly through tobacco smoke and ingestion of food contaminated with combustion products.

Toxicology[]

Many investigations indicate that anthracene is noncarcinogenic: "consistently negative findings in numerous in vitro and in vivo genotoxicity tests". Early experiments suggested otherwise because crude samples were contaminated with other . Furthermore, it is readily biodegraded in soil. It is especially susceptible to degradation in the presence of light.[21]

See also[]

  • 9,10-Dithioanthracene, derivative with two thiol groups added to the central ring
  • Phenanthrene
  • Tetracene

References[]

  1. ^ Jump up to: a b c d Haynes, p. 3.28
  2. ^ Haynes, p. 5.157
  3. ^ Jump up to: a b c d e f Seidell, Atherton; Linke, William F. (1919). Solubilities of Inorganic and Organic Compounds (2nd ed.). New York: D. Van Nostrand Company. pp. 81.
  4. ^ Haynes, p. 6.116
  5. ^ Jump up to: a b c Anthracene in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD), http://webbook.nist.gov (retrieved 2014-06-22)
  6. ^ Haynes, p. 5.157
  7. ^ Haynes, p. 3.579
  8. ^ Jump up to: a b "Properties of Anthracene". www.infotherm.com. Wiley Information Services GmbH. Archived from the original on 2014-11-01. Retrieved 2014-06-22.
  9. ^ Jump up to: a b c d Douglas, Bodie E.; Ho, Shih-Ming (2007). Structure and Chemistry of Crystalline Solids. New York: Springer Science+Business Media, Inc. p. 289. ISBN 978-0-387-26147-8.
  10. ^ Haynes, p. 5.41
  11. ^ Jump up to: a b c d e Sigma-Aldrich Co., Anthracene. Retrieved on 2014-06-22.
  12. ^ "MSDS of Anthracene". www.fishersci.ca. Fisher Scientific. Retrieved 2014-06-22.
  13. ^ Lindsey, Jonathan; et al. "Anthracene". PhotochemCAD. Retrieved 20 February 2014.
  14. ^ Freitalite, Mindat, https://www.mindat.org/min-54360.html
  15. ^ Bass, K. C. (1962). "9,10-Dihydroanthracene". Organic Syntheses. 42: 48. doi:10.15227/orgsyn.042.0048.
  16. ^ Rickborn, Bruce (1998). "The Retro-Diels-Alder Reaction Part I. C−C Dienophiles". Organic Reactions. pp. 1–393. doi:10.1002/0471264180.or052.01. ISBN 978-0471264187.
  17. ^ Bouas-Laurent, Henri; Desvergne, Jean-Pierre; Castellan, Alain; Lapouyade, Rene (2000). "Photodimerization of anthracenes in fluid solution: Structural aspects". Chemical Society Reviews. 29: 43–55. doi:10.1039/a801821i.
  18. ^ Charleton, Kimberly D. M.; Prokopchuk, Ernest M. (2011). "Coordination Complexes as Catalysts: The Oxidation of Anthracene by Hydrogen Peroxide in the Presence of VO(acac)2". Journal of Chemical Education. 88 (8): 1155–1157. Bibcode:2011JChEd..88.1155C. doi:10.1021/ed100843a.
  19. ^ Škalamera, Đani; Veljković, Jelena; Ptiček, Lucija; Sambol, Matija; Mlinarić-Majerski, Kata; Basarić, Nikola (2017). "Synthesis of asymmetrically disubstituted anthracenes". Tetrahedron. 73 (40): 5892–5899. doi:10.1016/j.tet.2017.08.038.
  20. ^ Heilbron, I. M.; Heaton, J. S. (1923). "9,10-Dibromoanthracene". Organic Syntheses. 3: 41. doi:10.15227/orgsyn.003.0041.
  21. ^ Jump up to: a b Collin, Gerd; Höke, Hartmut and Talbiersky, Jörg (2006) "Anthracene" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim. doi:10.1002/14356007.a02_343.pub2
  22. ^ Zeitler, Alex (2012-06-27) Conformal Coating 101: General Overview, Process Development, and Control Methods. BTW, Inc.
  23. ^ 1-Hydroxyanthracene. NIST datapage
  24. ^ 2-Hydroxyanthracene. NIST datapage

Cited sources[]

  • Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). CRC Press. ISBN 1439855110.

External links[]

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