Editing Pyrene

{{short description|Chemical compound}}
{{other uses}}
{{chembox
| Watchedfields  = changed
| verifiedrevid  = 464376838
| Name           = Pyrene
| ImageFile      = Pyrene.svg
| ImageSize      = 190px
| ImageAlt       = Structural formula of pyrene
| ImageFile1     = Pyrene molecule from xtal ball.png
| ImageSize1     = 200px
| ImageAlt1      = Ball-and-stick model of the pyrene molecule
| ImageFile2 = Pyrene crystal 1.jpg
| PIN            = Pyrene<ref>{{cite book |author=[[International Union of Pure and Applied Chemistry]] |date=2014 |title=Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 |publisher=[[Royal Society of Chemistry|The Royal Society of Chemistry]] |pages=206 |doi=10.1039/9781849733069 |isbn=978-0-85404-182-4}}</ref>
| OtherNames     = Benzo[''def'']phenanthrene
| Section1       = {{Chembox Identifiers
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 39106
| SMILES = c1cc2cccc3c2c4c1cccc4cc3
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 29153
| PubChem = 31423
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C14335
| 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
| InChIKey = BBEAQIROQSPTKN-UHFFFAOYAB
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 279564
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C16H10/c1-3-11-7-9-13-5-2-6-14-10-8-12(4-1)15(11)16(13)14/h1-10H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = BBEAQIROQSPTKN-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 129-00-0
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 9E0T7WFW93
| RTECS = UR2450000
| Beilstein = 1307225
| Gmelin = 84203
  }}
| Section2       = {{Chembox Properties
| C=16 | H=10
| Appearance = colorless solid
(yellow impurities are often found at trace levels in many samples).
| Density = 1.271 g/cm<sup>3</sup><ref name=crc>Haynes, p. 3.472</ref>
| Solubility =  0.049 mg/L (0 °C)<br>0.139 mg/L (25 °C)<br>2.31 mg/L (75 °C)<ref>Haynes, p. 5.162</ref>
| MeltingPtC = 150.62
| MeltingPt_ref = <ref name=crc/>
| BoilingPtC = 394
| BoilingPt_ref = <ref name=crc/>
| MagSus = −147·10<sup>−6</sup> cm<sup>3</sup>/mol<ref>Haynes, p. 3.579</ref>
| LogP = 5.08<ref>Haynes, p. 5.176</ref>
| BandGap = 2.02 eV<ref>Haynes, p. 12.96</ref>
  }}
| Section3       = {{Chembox Structure
| Structure_ref=<ref>{{cite journal|doi=10.1107/S0365110X65001494 |title=The crystal and molecular structure of pyrene |date=1965 |last1=Camerman |first1=A. |last2=Trotter |first2=J. |journal=Acta Crystallographica |volume=18 |issue=4 |pages=636–643 |doi-access=free }}</ref>
| CrystalStruct = [[Monoclinic]]
| SpaceGroup = P2<sub>1</sub>/a
| PointGroup = 
| LattConst_a = 13.64 Å
| LattConst_b = 9.25 Å
| LattConst_c = 8.47 Å
| LattConst_alpha = 
| LattConst_beta = 100.28
| LattConst_gamma = 
| LattConst_ref =
| LattConst_Comment = 
| UnitCellVolume = 
| UnitCellFormulas = 4
  }}
| Section4       = {{Chembox Thermochemistry
| Thermochemistry_ref=<ref>Haynes, pp. 5.34, 6.161</ref>
| HeatCapacity = 229.7 J/(K·mol)
| Entropy = 224.9&nbsp;J·mol<sup>−1</sup>·K<sup>−1</sup>
| DeltaHf = 125.5&nbsp;kJ·mol<sup>−1</sup>
| DeltaHfus =  17.36&nbsp;kJ·mol<sup>−1</sup>
}}
| Section7       = {{Chembox Hazards
| ExternalSDS =
| MainHazards = irritant
| GHSPictograms = {{GHS07}}{{GHS09}}
| GHSSignalWord = Warning
| HPhrases = {{HPhrases|H315 |H319 |H335 |H410 }}
| PPhrases = {{PPhrases|P261, |P264, |P271, |P273, |P280, |P302+P352, |P304+P340, |P305+P351+P338, |P312, |P321, |P332+P313, |P337+P313, |P362, |P391, |P403+P233, |P405|P501}}
| GHS_ref  =<ref>GHS: [https://pubchem.ncbi.nlm.nih.gov/compound/31423 PubChem]</ref>
| NFPA-H = 2
| NFPA-F = 1
| NFPA-R = 0
| FlashPt = non-flammable
  }}
| Section8       = {{Chembox Related
| OtherFunction_label = PAHs
| OtherFunction = [[benzopyrene]]
  }}
}}

'''Pyrene''' is a [[polycyclic aromatic hydrocarbon]] (PAH) consisting of four fused [[benzene]] rings, resulting in a flat [[Aromaticity|aromatic]] system.  The chemical formula is {{chem2|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 [[Combustion#Incomplete|incomplete combustion]] of organic compounds.<ref>{{cite journal |doi=10.1021/cr100428a|title=Pyrene-Based Materials for Organic Electronics|year=2011|last1=Figueira-Duarte|first1=Teresa M.|last2=Müllen|first2=Klaus|journal=Chemical Reviews|volume=111|issue=11|pages=7260–7314|pmid=21740071}}</ref>

==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 (chemistry)|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.<ref name=Ullmann>Senkan, Selim and Castaldi, Marco (2003) "Combustion" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim.</ref>

===Reactions===
Oxidation with [[Chromate ion|chromate]] affords perinaphthenone and then naphthalene-1,4,5,8-tetracarboxylic acid. Pyrene undergoes a series of [[hydrogenation]] reactions and is susceptible to halogenation, [[Diels-Alder]] additions, and nitration, all with varying degrees of selectivity.<ref name=Ullmann/>  Bromination occurs at one of the 3-positions.<ref>{{cite journal | last1 = Gumprecht | first1 = W. H. | year = 1968 | title = 3-Bromopyrene | journal = Org. Synth. | volume = 48 | page = 30 | doi = 10.15227/orgsyn.048.0030 }}</ref>

Reduction with sodium affords the radical anion. From this anion, a variety of pi-arene complexes can be prepared.<ref>{{cite journal |doi=10.1107/S2053229614015290|title=Bis(pyrene)metal complexes of vanadium, niobium and titanium: Isolable homoleptic pyrene complexes of transition metals|year=2014|last1=Kucera|first1=Benjamin E.|last2=Jilek|first2=Robert E.|last3=Brennessel|first3=William W.|last4=Ellis|first4=John E.|journal=Acta Crystallographica Section C: Structural Chemistry|volume=70|issue=8|pages=749–753|pmid=25093352}}</ref>

===Photophysics===

Pyrene and its derivatives are used commercially to make [[dye]]s 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&nbsp;nm in DCM. The emission is close to the absorption, but moving at 375&nbsp;nm.<ref name=":0">{{Cite journal|last1=Tagmatarchis|first1=Nikos|last2=Ewels|first2=Christopher P.|last3=Bittencourt|first3=Carla|last4=Arenal|first4=Raul|last5=Pelaez-Fernandez|first5=Mario|last6=Sayed-Ahmad-Baraza|first6=Yuman|last7=Canton-Vitoria|first7=Ruben|date=2017-06-05|title=Functionalization of MoS 2 with 1,2-dithiolanes: toward donor-acceptor nanohybrids for energy conversion|journal=npj 2D Materials and Applications|language=en|volume=1|issue=1|pages=13|doi=10.1038/s41699-017-0012-8|issn=2397-7132|doi-access=free|hdl=10261/367520|hdl-access=free}}</ref>  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&nbsp;K).  Pyrene was the first molecule for which [[excimer]] behavior was discovered.<ref>{{cite journal |last1=Van Dyke |first1=David A. |last2=Pryor |first2=Brian A. |last3=Smith |first3=Philip G. |last4=Topp |first4=Michael R. |title=Nanosecond Time-Resolved Fluorescence Spectroscopy in the Physical Chemistry Laboratory: Formation of the Pyrene Excimer in Solution |journal=Journal of Chemical Education |date=May 1998 |volume=75 |issue=5 |pages=615 |doi=10.1021/ed075p615|bibcode=1998JChEd..75..615V }}</ref> Such excimer appears around 450&nbsp;nm.  [[Theodor Förster]] reported this in 1954.<ref>{{cite journal |last1=Förster |first1=Th. |last2=Kasper |first2=K. |title=Ein Konzentrationsumschlag der Fluoreszenz. |journal=Zeitschrift für Physikalische Chemie |date=June 1954 |volume=1 |issue=5_6 |pages=275–277 |doi=10.1524/zpch.1954.1.5_6.275}}</ref>

==Applications==
{{multiple image
| align = left
| direction = vertical
| width = 180
| image1 = Br4Py self-assembly on Au.jpg
| caption1 = 
| image2 = Br4Py self-assembly on Au 2.jpg
| caption2 = [[Scanning tunneling microscopy|STM]] image of self-assembled Br<sub>4</sub>Py molecules on Au(111) surface (top) and its model (bottom; pink spheres are Br atoms).<ref>{{cite journal|doi=10.1039/C4CC02753A |title=Self-assembly of pyrene derivatives on Au(111): Substituent effects on intermolecular interactions |journal=Chem. Commun. |volume=50 |issue=91 |pages=14089–92 |year=2014 |last1=Pham |first1=Tuan Anh |last2=Song |first2=Fei |last3=Nguyen |first3=Manh-Thuong |last4=Stöhr |first4=Meike |pmid=24905327 |doi-access=free }}</ref>
}}
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.[[File:Pyrene-numbering.svg|thumb|190px|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.<ref name=":0" />

==Safety and environmental factors==
Although it is not as problematic as [[benzopyrene]], [[animal studies]] have shown pyrene is [[toxic]] to the [[kidneys]] and [[liver]]. It is now known that pyrene affects several living functions in fish and algae.<ref>{{Cite journal|last1=Oliveira|first1=M.|last2=Ribeiro|first2=A.|last3=Hylland|first3=K.|last4=Guilhermino|first4=L.|title=Single and combined effects of microplastics and pyrene on juveniles (0+ group) of the common goby Pomatoschistus microps (Teleostei, Gobiidae)|journal=Ecological Indicators|volume=34|pages=641–647|doi=10.1016/j.ecolind.2013.06.019|year=2013}}</ref><ref>{{Cite journal|last1=Oliveira|first1=M.|last2=Gravato|first2=C.|last3=Guilhermino|first3=L.|title=Acute toxic effects of pyrene on Pomatoschistus microps (Teleostei, Gobiidae): Mortality, biomarkers and swimming performance|journal=Ecological Indicators|volume=19|pages=206–214|doi=10.1016/j.ecolind.2011.08.006|year=2012}}</ref><ref>{{Cite journal|last1=Oliveira|first1=M.|last2=Ribeiro|first2=A.|last3=Guilhermino|first3=L.|title=Effects of exposure to microplastics and PAHs on microalgae Rhodomonas baltica and Tetraselmis chuii|journal=Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology|volume=163|pages=S19–S20|doi=10.1016/j.cbpa.2012.05.062|year=2012}}</ref><ref>{{Cite journal|last1=Oliveira|first1=M.|last2=Ribeiro|first2=A.|last3=Guilhermino|first3=L.|title=Effects of short-term exposure to microplastics and pyrene on Pomatoschistus microps (Teleostei, Gobiidae)|journal=Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology|volume=163|pages=S20|doi=10.1016/j.cbpa.2012.05.063|year=2012}}</ref>

Its biodegradation has been heavily examined.  The process commences with dihydroxylation at each of two kinds of CH=CH linkages.<ref>{{cite journal |doi=10.3390/ijerph6010278|doi-access=free|title=Bacterial Degradation of Aromatic Compounds|year=2009|last1=Seo|first1=Jong-Su|last2=Keum|first2=Young-Soo|last3=Li|first3=Qing|journal=International Journal of Environmental Research and Public Health|volume=6|issue=1|pages=278–309|pmid=19440284|pmc=2672333}}</ref> Experiments in pigs show that urinary [[1-hydroxypyrene]] is a metabolite of pyrene, when given orally.<ref>{{cite journal|doi=10.3109/00498258309052279|pmid=6659544|title=Identification of 1-hydroxypyrene as a major metabolite of pyrene in pig urine|journal=Xenobiotica|volume=13|issue=7|pages=415–20|year=1983|last1=Keimig|first1=S. D.|last2=Kirby|first2=K. W.|last3=Morgan|first3=D. P.|last4=Keiser|first4=J. E.|last5=Hubert|first5=T. D.}}</ref>

==See also==
* [[List of interstellar and circumstellar molecules]]
* [[Perhydropyrene]]

==References==
{{Reflist}}

==Cited sources==
*{{cite book |ref=Haynes| editor= Haynes, William M. | date = 2016| title = [[CRC Handbook of Chemistry and Physics]] | edition = 97th | publisher = [[CRC Press]] | isbn = 9781498754293}}

==Further reading==
* {{cite book | last = Birks | first = J. B. | title = Photophysics of Aromatic Molecules | location = London | publisher = Wiley | year = 1969 }}
* {{cite book | last = Valeur | first = B. | title = Molecular Fluorescence: Principles and Applications | location = New York | publisher = Wiley-VCH | year = 2002 }}
* {{cite journal |last1=Birks |first1=J. B. |title=Excimers |journal=Reports on Progress in Physics |date=1975 |volume=38 |issue=8 |pages=903–974 |doi=10.1088/0034-4885/38/8/001 |bibcode=1975RPPh...38..903B |s2cid=240065177 |language=en |issn=0034-4885}}
* {{cite book | last = Fetzer | first = J. C. | title = The Chemistry and Analysis of the Large Polycyclic Aromatic Hydrocarbons | location = New York | publisher = Wiley | year = 2000 }}

{{Hydrocarbons}}
{{PAHs}}
{{Molecules detected in outer space}}
{{Authority control}}

[[Category:Pyrenes]]
[[Category:Polycyclic aromatic hydrocarbons]]
[[Category:PBT substances]]