Chemistry:Anthracene

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Anthracene
Skeletal formula and numbering system of anthracene
Ball-and-stick model of the anthracene molecule
Anthracene
Names
IUPAC name
Anthracene
Identifiers
3D model (JSmol)
1905429
ChEBI
ChEMBL
ChemSpider
DrugBank
EC Number
  • 217-004-5
67837
KEGG
RTECS number
  • CA9350000
UNII
Properties
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
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)
19 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]
−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
Monoclinic (290 K)[9]
P21/b[9]
D52h[9]
a = 8.562 Å, b = 6.038 Å, c = 11.184 Å[9]
α = 90°, β = 124.7°, γ = 90°
Thermochemistry[10]
210.5 J/(mol·K)
207.5 J/(mol·K)
129.2 kJ/mol
7061 kJ/mol[5]
Hazards
GHS pictograms GHS07: HarmfulGHS09: Environmental hazard[11]
GHS Signal word Warning
H302, H305, H315, H319, H335, H410[11]
P261, P273, P305+351+338, P501[11]
NFPA 704 (fire diamond)
Flash point 121 °C (250 °F; 394 K)[11]
540 °C (1,004 °F; 813 K)[11]
Lethal dose or concentration (LD, LC):
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).
☑Y verify (what is ☑Y☒N ?)
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, for example from o-tolyl phenyl ketone.[15]

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.[16]

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.[17][18]

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.[19]

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.[20] Bromination of anthracene gives 9,10-dibromoanthracene.[21]

Uses

Anthracene is converted mainly to anthraquinone, a precursor to dyes.[22]

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.[23]

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)[24][25] are pharmacologically active. Anthracene may also be found with multiple hydroxyl groups, as in 9,10-dihydroxyanthracene.

Learned uses of Anthracene, includes in the synthesis of Bisantrene, Trazitiline, Benzoctamine & BRN 2382808 (antidepressant with CNS stimulant properties).

BRN 2382808.svg

In addition, P. Rajagopalan reported a cycloaddition antidepressant made from anthracene with a potency that easily surpasses amitriptyline or imipramine.[26]

P. Rajagopalan.svg

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 polycyclic aromatic hydrocarbons. Furthermore, it is readily biodegraded in soil. It is especially susceptible to degradation in the presence of light.[22]

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 Haynes, p. 3.28
  2. ↑ Haynes, p. 5.157
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Seidell, Atherton; Linke, William F. (1919). Solubilities of Inorganic and Organic Compounds (2nd ed.). New York: D. Van Nostrand Company. pp. 81. https://archive.org/details/solubilitiesino01seidgoog. 
  4. ↑ Haynes, p. 6.116
  5. ↑ 5.0 5.1 5.2 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. ↑ 8.0 8.1 "Properties of Anthracene". Wiley Information Services GmbH. http://www.infotherm.com/static/molpages/02/32/mol23245.html. 
  9. ↑ 9.0 9.1 9.2 9.3 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. https://books.google.com/books?id=hYRCAAAAQBAJ&pg=PA289. 
  10. ↑ Haynes, p. 5.41
  11. ↑ 11.0 11.1 11.2 11.3 11.4 Sigma-Aldrich Co., Anthracene. Retrieved on 2014-06-22.
  12. ↑ "MSDS of Anthracene". Fisher Scientific. https://www.fishersci.ca/viewmsds.do?catNo=AC104860050. 
  13. ↑ Lindsey, Jonathan. "Anthracene". PhotochemCAD. http://omlc.ogi.edu/spectra/PhotochemCAD/html/022.html. 
  14. ↑ Freitalite, Mindat, https://www.mindat.org/min-54360.html
  15. ↑ "Anthracene" (in en). https://www.acs.org/content/acs/en/molecule-of-the-week/archive/a/anthracene.html. 
  16. ↑ Bass, K. C. (1962). "9,10-Dihydroanthracene". Organic Syntheses 42: 48. doi:10.15227/orgsyn.042.0048. 
  17. ↑ Rickborn, Bruce (1998). "The Retro– <SCP>D</SCP> iels– <SCP>A</SCP> lder Reaction Part <SCP>I</SCP> . <SCP>C</SCP>  <SCP>C</SCP> Dienophiles". Organic Reactions. pp. 1–393. doi:10.1002/0471264180.or052.01. ISBN 978-0471264187. 
  18. ↑ 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. 
  19. ↑ 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. doi:10.1021/ed100843a. Bibcode: 2011JChEd..88.1155C. 
  20. ↑ 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. 
  21. ↑ Heilbron, I. M.; Heaton, J. S. (1923). "9,10-Dibromoanthracene". Organic Syntheses 3: 41. doi:10.15227/orgsyn.003.0041. 
  22. ↑ 22.0 22.1 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
  23. ↑ Zeitler, Alex (2012-06-27) Conformal Coating 101: General Overview, Process Development, and Control Methods. BTW, Inc.
  24. ↑ 1-Hydroxyanthracene. NIST datapage
  25. ↑ 2-Hydroxyanthracene. NIST datapage
  26. ↑ "Synthetic CNS agents. 1. (.+-.)-1,2,3,4,4a,5,10,10a-Octahydro-5,10[1',2']-benzenobenz[g]isoquinoline hydrochloride. A new, highly potent, potential antidepressant". Journal of Medicinal Chemistry 27 (8): 946–947. August 1984. doi:10.1021/jm00374a002. PMID 6747994. 

Cited sources

External links



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