{{short description|Polycyclic aromatic hydrocarbon composed of three fused benzene rings}} {{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 444046459 | ImageFile=Phenanthrene-numbering.svg | ImageSize=180px | ImageFile1=Phenanthrene molecule ball.png | ImageSize1=180px | ImageAlt1 = Ball-and-stick model of the phenanthrene molecule | ImageFile2 = Phenanthrene C14H10.JPG | ImageName2 = Phenanthrene | PIN = Phenanthrene <!-- Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) --> |Section1={{Chembox Identifiers | CASNo_Ref = {{cascite|correct|CAS}} | CASNo=85-01-8 | PubChem=995 | ChEBI_Ref = {{ebicite|changed|EBI}} | ChEBI = 28851 | KEGG_Ref = {{keggcite|correct|kegg}} | KEGG = C11422 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 448J8E5BST | SMILES = C1=CC=C2C(=C1)C=CC3=CC=CC=C32 | EINECS = 266-028-2 | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID = 970 | InChI = 1/C14H10/c1-3-7-13-11(5-1)9-10-12-6-2-4-8-14(12)13/h1-10H | InChIKey = YNPNZTXNASCQKK-UHFFFAOYAC | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/C14H10/c1-3-7-13-11(5-1)9-10-12-6-2-4-8-14(12)13/h1-10H | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = YNPNZTXNASCQKK-UHFFFAOYSA-N | RTECS = | MeSHName = C031181 | Beilstein = 1905428 | Gmelin = 28699 }} |Section2={{Chembox Properties | C=14 | H=10 | Appearance=Colorless solid | Density=1.18 g/cm<sup>3</sup><ref name=GESTIS/> | MeltingPtC=101 | MeltingPt_ref = <ref name=GESTIS>{{GESTIS|ZVG=22900|CAS=85-01-8}}</ref> | BoilingPtC=332 | BoilingPt_ref = <ref name=GESTIS/> | Solubility=1.6 mg/L<ref name=GESTIS/> | MagSus = −127.9·10<sup>−6</sup> cm<sup>3</sup>/mol }} |Section3={{Chembox Hazards | NFPA-H = 1|NFPA-F = 1|NFPA-R=0|NFPA-S = | MainHazards= | FlashPtC = 171 | FlashPt_ref = <ref name=GESTIS/> | AutoignitionPt = }} |Section4={{Chembox Structure | PointGroup = C<sub>2v</sub><ref>Peter Atkins, J. D. P., Atkins' Physical Chemistry. Oxford: 2010. P.&nbsp;443.</ref> | Dipole = 0 D }} }}

'''Phenanthrene''' is a polycyclic aromatic hydrocarbon (PAH) with formula C<sub>14</sub>H<sub>10</sub>, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics, pesticides, explosives, and drugs. It has also been used to make bile acids, cholesterol and steroids.<ref name="factsheet">{{cite web |title=Phenanthrene Fact Sheet |url=https://archive.epa.gov/epawaste/hazard/wastemin/web/pdf/phenanth.pdf |website=archive.epa.gov |publisher=U.S. Environmental Protection Agency |access-date=19 July 2019}}</ref>

Phenanthrene occurs naturally and also is a man-made chemical. Commonly, humans are exposed to phenanthrene through inhalation of cigarette smoke, but there are many routes of exposure. Animal studies have shown that phenanthrene is a potential carcinogen.<ref name="factsheet" /> However, according to IARC, it is not identified as a probable, possible or confirmed human carcinogen.<ref>{{cite web |title=Phenanthrene |website=Sigma-Alrdich |url=https://www.sigmaaldrich.com/catalog/product/aldrich/p11409}}</ref>

Phenanthrene's three fused rings are angled as in the phenacenes, rather than straight as in the acenes. The compounds with a phenanthrene skeleton but with nitrogen atoms in place of CH sites are known as phenanthrolines.

== History and etymology == Phenanthrene was discovered in coal tar in 1872 independently by Carl Graebe (article manuscript received on November 1st<ref>{{Cite journal |last=Graebe |first=C. |date=1872 |title=Ueber einen neuen dem Anthracen isomeren Kohlenwasserstoff |url=https://books.google.com/books?id=cwaLZrjMd0oC&pg=PA861 |journal=Berichte der deutschen chemischen Gesellschaft |language=en |volume=5 |issue=2 |pages=861–863 |doi=10.1002/cber.18720050279 |issn=0365-9496|url-access=subscription }}</ref>) as well as by Wilhelm Rudolph Fittig and his doctoral student {{Ill|Eugen Ostermayer|de}} (manuscript received on November 19th<ref>{{Cite journal |last=Ostermayer |first=E. |last2=Fittig |first2=R. |date=1872 |title=Ueber einen neuen Kohlenwasserstoff aus dem Steinkohlentheer |url=https://books.google.com/books?id=cwaLZrjMd0oC&pg=PA933 |journal=Berichte der deutschen chemischen Gesellschaft |language=en |volume=5 |issue=2 |pages=933–937 |doi=10.1002/cber.187200502100 |issn=0365-9496}}</ref> but Ostermayer defended his dissertation in August<ref>{{Cite book |last=Ostermayer |first=Eugen |url=https://books.google.com/books?id=K5NTAAAAcAAJ |title=Ueber einen neuen Kohlenwasserstoff im Steinkohlentheeröl: Inaugural-Dissertation |date=1872 |publisher=Druck v. Fues |language=de}}</ref>). Fittig and Ostermayer were able to determine the structure of the compound by oxidizing it first to a corresponding quinone and then to diphenic acid, and soon Graebe confirmed it by a synthesis from stilbene.<ref>{{Cite journal |last=Graebe |first=C. |date=1873 |title=Ueber Synthese des Phenanthrens |url=https://books.google.com/books?id=vCxJAAAAYAAJ&pg=PA125 |journal=Berichte der deutschen chemischen Gesellschaft |language=en |volume=6 |issue=1 |pages=125–127 |doi=10.1002/cber.18730060147 |issn=0365-9496}}</ref>

Prior to February 1873 Fittig sent a letter to Graebe where he proposed to name the hydrocarbon phenanthrene ({{Langx|de|Phenanthren}}) in order to account for its similarity to biphenyl and anthracene, which was swiftly adopted.<ref>{{Cite journal |last=Graebe |first=C. |date=1873 |title=Ueber das Verhalten der Chinone beim Erhitzen mit Natronkalk |url=https://books.google.com/books?id=vCxJAAAAYAAJ&pg=PA63 |journal=Berichte der deutschen chemischen Gesellschaft |volume=6 |issue=1 |pages=63–66 |doi=10.1002/cber.18730060124 |issn=0365-9496|url-access=subscription }}</ref>

==Physical properties==

Phenanthrene is nearly insoluble in water but is soluble in most low-polarity organic solvents such as toluene, carbon tetrachloride, ether, chloroform, acetic acid and benzene.

Phenanthrene is fluorescent under ultraviolet light, exhibiting a large Stoke shift.<ref>{{Cite web |title=Spectrum [Phenanthrene] {{!}} AAT Bioquest |url=https://www.aatbio.com/fluorescence-excitation-emission-spectrum-graph-viewer/phenanthrene |access-date=2024-07-30 |website=www.aatbio.com}}</ref> It can be used in scintillators.

==Chemistry==

Reactions of phenanthrene typically occur at the 9 and 10 positions, including: * Oxidation with chromic acid gives phenanthrenequinone.<ref>Organic Syntheses, Coll. Vol.&nbsp;4, [http://www.orgsynth.org/orgsyn/pdfs/CV4P0757.pdf p.&nbsp;757] (1963); Vol.&nbsp;34, p.&nbsp;76 (1954).</ref> * Organic reduction to 9,10-dihydrophenanthrene with hydrogen gas and raney nickel<ref>Organic Syntheses, Coll. Vol.&nbsp;4, [http://www.orgsynth.org/orgsyn/pdfs/CV4P0313.pdf p.&nbsp;313] (1963); Vol.&nbsp;34, p.&nbsp;31 (1954).</ref> * Electrophilic halogenation to 9-bromophenanthrene with bromine<ref>Organic Syntheses, Coll. Vol.&nbsp;3, [http://www.orgsynth.org/orgsyn/pdfs/CV3P0134.pdf p.&nbsp;134] (1955); Vol.&nbsp;28, p.&nbsp;19 (1948).</ref> * Aromatic sulfonation to 2 and 3-phenanthrenesulfonic acids with sulfuric acid<ref>Organic Syntheses, Coll. Vol.&nbsp;2, [http://www.orgsynth.org/orgsyn/pdfs/CV2P0482.pdf p.&nbsp;482] (1943); Vol.&nbsp;16, p.&nbsp;63 (1936).</ref> * Ozonolysis to diphenylaldehyde<ref>Organic Syntheses, Coll. Vol.&nbsp;5, [http://www.orgsynth.org/orgsyn/pdfs/CV5P0489.pdf p.&nbsp;489] (1973); Vol.&nbsp;41, p.&nbsp;41 (1961).</ref>

==Productions== Phenanthrene is extracted from coal tar, of which it comprises 5% by weight.<ref name=Ullmann/>

In principle it could be obtained by chemical synthesis. The '''Bardhan–Sengupta phenanthrene synthesis''' is a classic way to make phenanthrenes.<ref>{{cite book |year= 2010 |chapter= Bardhan Sengupta Synthesis |title= Comprehensive Organic Name Reactions and Reagents |volume= 49 |pages= 215–219 |doi= 10.1002/9780470638859.conrr049 |isbn= 978-0-470-63885-9 }}</ref> :480px|Bardhan–Senguptam phenanthrene synthesis

This process involves electrophilic aromatic substitution using a tethered cyclohexanol group using diphosphorus pentoxide, which closes the central ring onto an existing aromatic ring. Dehydrogenation using selenium aromatizes the other rings into aromatic ones as well. The aromatization of six-membered rings produces H<sub>2</sub>Se.

Phenanthrene can also be obtained photochemically from certain diarylethenes (Mallory reaction):thumb

Other synthesis routes include the Haworth reaction and the Wagner-Meerwein-type ring-expansion, as depicted below: thumbCommercially phenanthrene is not synthesized but extracted from the byproducts of coal coking, since it makes around 4–6% of coke oven coal tar.<ref>{{Cite journal |last=Ma |first=Zhi-Hao |last2=Wei |first2=Xian-Yong |last3=Liu |first3=Guang-Hui |last4=Liu |first4=Fang-Jing |last5=Zong |first5=Zhi-Min |date=2021-05-15 |title=Value-added utilization of high-temperature coal tar: A review |url=https://www.sciencedirect.com/science/article/abs/pii/S0016236120329501 |journal=Fuel |volume=292 |article-number=119954 |doi=10.1016/j.fuel.2020.119954 |issn=0016-2361|url-access=subscription }}</ref>

== Natural occurrences of the phenanthrene derivatives== Structure of morphinan, which features a partially reduced phenanthroline core|thumb|left|120px Morphinan is the chemical structure found in several psychoactive drugs, consisting of opiate analgesics, cough suppressants, and dissociative hallucinogens, among others. Examples morphine, codeine, and dextromethorphan (DXM).<ref name=Ullmann>{{cite book |doi=10.1002/14356007.a13_227.pub3 |chapter=Hydrocarbons |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2014 |last1=Schmidt |first1=Roland |last2=Griesbaum |first2=Karl |last3=Behr |first3=Arno |last4=Biedenkapp |first4=Dieter |last5=Voges |first5=Heinz-Werner |last6=Garbe |first6=Dorothea |last7=Paetz |first7=Christian |last8=Collin |first8=Gerd |last9=Mayer |first9=Dieter |last10=Höke |first10=Hartmut |pages=1–74 |isbn=978-3-527-30673-2 }}</ref>

Ravatite is a natural mineral consisting of phenanthrene.<ref>[https://webmineral.com/data/Ravatite.shtml Ravatite Mineral Data]</ref> It is found in small amounts among a few coal burning sites. Ravatite represents a small group of organic minerals.

=== In plants === {{Main article|Phenanthrenes}}Phenanthrene derivatives occur in plants as phenanthrenoids. They have been reported from flowering plants, mainly in the family Orchidaceae, and a few in the families Dioscoreaceae, Combretaceae and Betulaceae, as well as in the lower plant class Marchantiophyta (liverworts).<ref name="Kovacs">{{cite journal |last1=Kovács |first1=Adriána |last2=Vasas |first2=Andrea |last3=Hohmann |first3=Judit |year=2008 |title=Natural phenanthrenes and their biological activity |journal=Phytochemistry |volume=69 |issue=5 |pages=1084–1110 |bibcode=2008PChem..69.1084K |doi=10.1016/j.phytochem.2007.12.005 |pmid=18243254}}</ref>

==See also== * Chrysene * Anthracene * Phenanthroline

== References == {{reflist}}

== External links == * [http://www.scorecard.org/chemical-profiles/summary.tcl?edf_substance_id=85%2d01%2d8 Phenanthrene] at scorecard.org

{{Hydrocarbons}} {{PAHs}} {{Organic reactions}} {{Chemical classes of psychoactive drugs}} {{Authority control}}

Category:Phenanthrenes Category:Polycyclic aromatic hydrocarbons