{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 392374283 | Name =''para''-Terphenyl | Reference = | ImageFile = Para-terphenyl.png | ImageSize = | ImageName = Skeletal formula of para-terphenyl | ImageFile1 = Para-terphenyl-from-xtal-view-2-3D-bs-17.png | ImageSize1 = | ImageName1 = Ball-and-stick model of para-terphenyl | PIN = 1<sup>1</sup>,2<sup>1</sup>:2<sup>4</sup>,3<sup>1</sup>-Terphenyl<ref name=iupac2013>{{cite book | title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = The Royal Society of Chemistry | date = 2014 | location = Cambridge | page = 345 | doi = 10.1039/9781849733069-00130 | isbn = 978-0-85404-182-4}}</ref> | OtherNames = 1,1′:4′,1″-Terphenyl<ref name=iupac2013/><br />''p''-Terphenyl<br />1,4-Diphenylbenzene<br />''para''-Diphenylbenzene<br />''p''-Diphenylbenzene<br />''para''-Triphenyl<br />''p''-Triphenyl |Section1={{Chembox Identifiers | CASNo_Ref = {{cascite|correct|CAS}} | CASNo = 92-94-4 | CASNo_Comment = (''para'') | CASNo2_Ref = {{cascite|correct|CAS}} | CASNo2 = 92-06-8 | CASNo2_Comment = (''meta'') | CASNo3_Ref = {{cascite|correct|CAS}} | CASNo3 = 84-15-1 | CASNo3_Comment = (''ortho'') | CASNo4_Ref = {{cascite|correct|CAS}} | CASNo4 = 26140-60-3 | CASNo4_Comment = (unspecified) | Beilstein = 1908447 | ChEMBL1 = 491582 | ChEBI1 = 52242 | PubChem =7115 | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID = 6848 | ChemSpiderID_Comment = (''para'') | EC_number1 = 202-205-2 | RTECS1 = WZ6475000 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = GWP218ZY6F | UNII_Comment = (''para'') | UNII2_Ref = {{fdacite|correct|FDA}} | UNII2 = WOI2PSS0KX | UNII2_Comment = (''meta'') | UNII3_Ref = {{fdacite|correct|FDA}} | UNII3 = W5675R7KVW | UNII3_Comment = (''ortho'') | UNII4_Ref = {{fdacite|correct|FDA}} | UNII4 = LFX1C55D2Z | UNII4_Comment = (unspecified) | SMILES =C1=CC=C(C=C1)C2=CC=C(C=C2)C3=CC=CC=C3 | SMILES2 = c1ccc(cc1)c2ccc(cc2)c3ccccc3 | SMILES2_Comment = (''para'') | InChI = 1/C18H14/c1-3-7-15(8-4-1)17-11-13-18(14-12-17)16-9-5-2-6-10-16/h1-14H | InChI_Comment = (''para'') | InChIKey = XJKSTNDFUHDPQJ-UHFFFAOYAJ | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/C18H14/c1-3-7-15(8-4-1)17-11-13-18(14-12-17)16-9-5-2-6-10-16/h1-14H | StdInChI_Comment = (''para'') | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = XJKSTNDFUHDPQJ-UHFFFAOYSA-N }} |Section2={{Chembox Properties | C=18 | H=14 | Appearance =White powder<ref name=chemicalland21/> | Density = 1.24 g/cm<sup>3</sup> | MeltingPtC = 212 to 214 | MeltingPt_ref = <ref name=chemicalland21/><br>212-213 °C<ref name=Sigma>[http://www.sigmaaldrich.com/catalog/product/sial/257389?lang=en&region=US ''p''-Terphenyl] at Sigma-Aldrich</ref> | BoilingPtC = 389 | BoilingPt_ref = <ref name=Sigma/> | Solubility =Insoluble<ref name=chemicalland21/> | RefractIndex = 1.65<ref name="Cryos Beta">{{cite web | url = http://www.cryos-beta.kharkov.ua/organic.php | title = Organic molecular single crystals | publisher = cryos-beta.kharkov.ua }}</ref> }} |Section3={{Chembox Hazards | MainHazards = | FlashPtC = 207 | FlashPt_ref = <ref name=Sigma/> | AutoignitionPt = | GHSPictograms = {{GHS07}}{{GHS09}} | GHSSignalWord = Warning | HPhrases = {{H-phrases|315|319|335|400}} | PPhrases = {{P-phrases|261|264|271|273|280|302+352|304+340|305+351+338|312|321|332+313|337+313|362|391|403+233|405|501}} | NFPA-H = 2 | NFPA-F = 1 | NFPA-R = 0 | PEL = C 9 mg/m<sup>3</sup> (1 ppm)<ref>{{PGCH|0591}}</ref><ref>{{PGCH|0592}}</ref><ref>{{PGCH|0593}}</ref> }} }}

'''Terphenyls''' are a group of aromatic hydrocarbons. Also known as '''diphenylbenzenes''' or '''triphenyls''', they consist of a central benzene ring substituted with two phenyl groups. There are three substitution patterns: ''ortho''-terphenyl, ''meta''-terphenyl, and ''para''-terphenyl. Commercial grade terphenyl is generally a mixture of the three isomers. This mixture is used in the production of polychlorinated terphenyls, which were formerly used as heat storage and transfer agents.<ref name=chemicalland21>[http://chemicalland21.com/industrialchem/IUH/p-TERPHENYL.htm ''p''-Terphenyl] at chemicalland21.com</ref>

==Occurrence== ''p''-Terphenyl derivatives are found in various fungi and bacteria. One example is atromentin, a pigment found in some mushrooms. These natural ''p''-terphenyls are better described as diphenylquinones or diphenylhydroquinones. Some m-terphenyl compounds occur in plants.<ref>{{cite journal |doi=10.1021/cr050248c |title=Natural Terphenyls: Developments since 1877 |date=2006 |last1=Liu |first1=Ji-Kai |journal=Chemical Reviews |volume=106 |issue=6 |pages=2209–2223 |pmid=16771447 }}</ref> {{Gallery |File:ortho-terphenyl.png|''ortho''-Terphenyl |class1=skin-invert-image |File:meta-terphenyl.png|''meta''-Terphenyl |class2=skin-invert-image |File:para-terphenyl.png|''para''-Terphenyl |class3=skin-invert-image }}

==See also== * Biphenyl * Terpyridine * Terthiophene * Triphenylene * OMRE, experimental organic nuclear reactor that tested terphenyl as reactor coolant

==References== {{reflist}}

==External links== * [http://omlc.ogi.edu/spectra/PhotochemCAD/html/p-terphenyl.html p-Terphenyl] at the Oregon Laser Medical Center * [https://www.cdc.gov/niosh/npg/npgd0591.html o-Terphenyl], [https://www.cdc.gov/niosh/npg/npgd0592.html m-Terphenyl], [https://www.cdc.gov/niosh/npg/npgd0593.html p-Terphenyl] at Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health

Category:Aromatic hydrocarbons Category:Phenyl compounds Category:Nuclear reactor coolants