Pyrene

Source: Wikipedia, the free encyclopedia.
For other uses, see Pyrene (disambiguation).
Pyrene
Structural formula of pyrene
Ball-and-stick model of the pyrene molecule
Names
Preferred IUPAC name
Pyrene[1]
Other names
Benzo[def]phenanthrene
Identifiers
3D model (
JSmol
)
1307225
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard
 100.004.481 Edit this at Wikidata
84203
KEGG
RTECS number
  • UR2450000
UNII
  • InChI=1S/C16H10/c1-3-11-7-9-13-5-2-6-14-10-8-12(4-1)15(11)16(13)14/h1-10H checkY
    Key: BBEAQIROQSPTKN-UHFFFAOYSA-N checkY
  • InChI=1/C16H10/c1-3-11-7-9-13-5-2-6-14-10-8-12(4-1)15(11)16(13)14/h1-10H
    Key: BBEAQIROQSPTKN-UHFFFAOYAB
  • c1cc2cccc3c2c4c1cccc4cc3
Properties
C16H10
Molar mass 202.256 g·mol−1
Appearance colorless solid

(yellow impurities are often found at trace levels in many samples).

Density 1.271 g/cm3[2]
Melting point 150.62 °C (303.12 °F; 423.77 K)[2]
Boiling point 394 °C (741 °F; 667 K)[2]
0.049 mg/L (0 °C)
0.139 mg/L (25 °C)
2.31 mg/L (75 °C)[3]
log P 5.08[4]
Band gap 2.02 eV[5]
-147·10−6 cm3/mol[6]
Structure[7]
Monoclinic
P21/a
a = 13.64 Å, b = 9.25 Å, c = 8.47 Å
α = 90°, β = 100.28°, γ = 90°
4
Thermochemistry[8]
229.7 J/(K·mol)
224.9 J·mol−1·K−1
Std enthalpy of
formation
(ΔfH⦵298)
 125.5 kJ·mol−1
Enthalpy of fusion (ΔfH⦵fus)
 17.36 kJ·mol−1
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 irritant
GHS labelling:[9]
GHS07: Exclamation markGHS09: Environmental hazard
Warning
H315, H319, H335, H410
P261, P264, P271, P273, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
1
0
Flash point non-flammable
Related compounds
Related PAHs
 benzopyrene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Pyrene is a polycyclic aromatic hydrocarbon (PAH) consisting of four fused benzene rings, resulting in a flat aromatic system. The chemical formula is C16H10. This yellow-green solid is the smallest peri-fused PAH (one where the rings are fused through more than one face). Pyrene forms during incomplete combustion of organic compounds.[10]

Occurrence and properties

Pyrene was first isolated from coal tar, where it occurs up to 2% by weight. As a peri-fused PAH, pyrene is much more resonance-stabilized than its five-member-ring containing isomer fluoranthene. Therefore, it is produced in a wide range of combustion conditions. For example, automobiles produce about 1 μg/km.[11]

Reactions

Oxidation with

Diels-Alder additions, and nitration, all with varying degrees of selectivity.[11] Bromination occurs at one of the 3-positions.[12]

Reduction with sodium affords the radical anion. From this anion, a variety of pi-arene complexes can be prepared.[13]

Photophysics

Pyrene and its derivatives are used commercially to make dyes and dye precursors, for example pyranine and naphthalene-1,4,5,8-tetracarboxylic acid. It has strong absorbance in UV-Vis in three sharp bands at 330 nm in DCM. The emission is close to the absorption, but moving at 375 nm.[14] The morphology of the signals change with the solvent. Its derivatives are also valuable molecular probes via fluorescence spectroscopy, having a high quantum yield and lifetime (0.65 and 410 nanoseconds, respectively, in ethanol at 293 K). Pyrene was the first molecule for which excimer behavior was discovered.[15] Such excimer appears around 450 nm. Theodor Förster reported this in 1954.[16]

Applications

STM image of self-assembled Br4Py molecules on Au(111) surface (top) and its model (bottom; pink spheres are Br atoms).[17]

Pyrene's fluorescence emission spectrum is very sensitive to solvent polarity, so pyrene has been used as a probe to determine solvent environments. This is due to its excited state having a different, non-planar structure than the ground state. Certain emission bands are unaffected, but others vary in intensity due to the strength of interaction with a solvent.

Diagram showing the numbering and ring fusion locations of pyrene according to IUPAC nomenclature of organic chemistry.

Pyrenes are strong electron donor materials and can be combined with several materials in order to make electron donor-acceptor systems which can be used in energy conversion and light harvesting applications.[14]

Safety and environmental factors

Although it is not as problematic as

kidneys and liver. It is now known that pyrene affects several living functions in fish and algae.[18][19][20][21]

Its biodegradation has been heavily examined. The process commences with dihydroxylation at each of two kinds of CH=CH linkages.

1-hydroxypyrene is a metabolite of pyrene, when given orally.[23]

See also

References

  1. ISBN 978-0-85404-182-4
    .
  2. ^ a b c Haynes, p. 3.472
  3. ^ Haynes, p. 5.162
  4. ^ Haynes, p. 5.176
  5. ^ Haynes, p. 12.96
  6. ^ Haynes, p. 3.579
  7. doi:10.1107/S0365110X65001494
    .
  8. ^ Haynes, pp. 5.34, 6.161
  9. ^ GHS: PubChem
  10. PMID 21740071
    .
  11. ^ a b Senkan, Selim and Castaldi, Marco (2003) "Combustion" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim.
  12. doi:10.15227/orgsyn.048.0030
    .
  13. PMID 25093352
    .
  14. ^
    ISSN 2397-7132
    .
  15. doi:10.1021/ed075p615
    .
  16. doi:10.1524/zpch.1954.1.5_6.275
    .
  17. PMID 24905327
    .
  18. doi:10.1016/j.ecolind.2013.06.019
    .
  19. doi:10.1016/j.ecolind.2011.08.006
    .
  20. doi:10.1016/j.cbpa.2012.05.062
    .
  21. doi:10.1016/j.cbpa.2012.05.063
    .
  22. PMID 19440284
    .
  23. PMID 6659544
    .

Cited sources

Further reading
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