P-Cymene
{{DISPLAYTITLE:p-Cymene}}
{{chembox
|verifiedrevid = 414093009
|Name = p-Cymene
|ImageFileL1_Ref = {{chemboximage|correct|??}}
|ImageFileL1 = P-Cymol.svg
|ImageNameL1 = Skeletal formula
|ImageFileR1 = Cymene-3D-balls.png
|ImageNameR1 = Ball-and-stick model
|PIN = 1-Methyl-4-(propan-2-yl)benzene{{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 | pages = 139, 597 | doi = 10.1039/9781849733069-FP001 | isbn = 978-0-85404-182-4}}
|OtherNames = para-Cymene
4-Isopropyltoluene
4-Methylcumene
Paracymene
|Section1 = {{Chembox Identifiers
|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|ChemSpiderID = 7183
|UNII_Ref = {{fdacite|correct|FDA}}
|UNII = 1G1C8T1N7Q
|RTECS = GZ5950000
|UNNumber = 2046
|Gmelin = 305912
|Beilstein = 1903377
|KEGG_Ref = {{keggcite|correct|kegg}}
|KEGG = C06575
|InChIKey = HFPZCAJZSCWRBC-UHFFFAOYAD
|ChEMBL_Ref = {{ebicite|correct|EBI}}
|ChEMBL = 442915
|StdInChI_Ref = {{stdinchicite|correct|chemspider}}
|StdInChI = 1S/C10H14/c1-8(2)10-6-4-9(3)5-7-10/h4-8H,1-3H3
|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
|StdInChIKey = HFPZCAJZSCWRBC-UHFFFAOYSA-N
|CASNo = 99-87-6
|CASNo_Ref = {{cascite|correct|CAS}}
|EINECS = 202-796-7
|PubChem = 7463
|ChEBI = 28768
|3DMet = B00975
|SMILES = c1cc(ccc1C(C)C)C
|InChI = 1/C10H14/c1-8(2)10-6-4-9(3)5-7-10/h4-8H,1-3H3
}}
|Section2 = {{Chembox Properties
|C=10 | H=14
|Density = 0.857 g/cm3
|MeltingPtC = -68
|BoilingPtC = 177
|Solubility = 23.4 mg/L
|Appearance = Colourless liquid
|MagSus = {{val|-1.028|e=-4|u=cm3/mol}}
|RefractIndex = 1.4908 (at 20 °C) {{cite journal|author1=Pabst, Florian|author2=Blochowicz, Thomas |title=On the intensity of light scattered by molecular liquids - Comparison of experiment and quantum chemical calculations|journal=The Journal of Chemical Physics|language=en|date=December 2022|volume=157|issue=24|pages=244501|doi=10.1063/5.0133511|pmid=36586992 |bibcode=2022JChPh.157x4501P |doi-access=free}}
}}
|Section3 = {{Chembox Hazards
|GHSPictograms = {{GHS02}}{{GHS08}}{{GHS09}}
|GHSSignalWord = Danger
|HPhrases = {{H-phrases|226|304|411}}
|PPhrases = {{P-phrases|210|233|240|241|242|243|273|280|301+310|303+361+353|331|370+378|391|403+235|405|501}}
|FlashPtC = 47
|AutoignitionPtC = 435
}}
}}
p-Cymene is a naturally occurring aromatic organic compound. It is classified as an alkylbenzene related to monocyclic monoterpenes.{{cite journal |last=Balahbib |first=Abdelaali |last2=El Omari |first2=Nasreddine |last3=Hachlafi |first3=Naoufal EL. |last4=Lakhdar |first4=Fatima |last5=El Menyiy |first5=Naoual |last6=Salhi |first6=Najoua |last7=Mrabti |first7=Hanae Naceiri |last8=Bakrim |first8=Saad |last9=Zengin |first9=Gokhan |last10=Bouyahya |first10=Abdelhakim |date=2021-07-01 |title=Health beneficial and pharmacological properties of p-cymene |url=https://www.sciencedirect.com/science/article/abs/pii/S0278691521002921#:~:text=p%2Dcymene%20also%20known%20as,of%20terpenes%2C%20especially%20monocyclic%20monoterpenes. |journal=Food and Chemical Toxicology |volume=153 |pages=112259 |doi=10.1016/j.fct.2021.112259 |issn=0278-6915|url-access=subscription }} Its structure consists of a benzene ring para-substituted with a methyl group and an isopropyl group. p-Cymene is insoluble in water, but miscible with organic solvents.
Isomers and production
In addition to p-cymene, two less common geometric isomers are o-cymene, in which the alkyl groups are ortho-substituted, and m-cymene, in which they are meta-substituted. p-Cymene is the only natural isomer, as expected from the terpene rule. All three isomers form the group of cymenes.
Cymene is also produced by alkylation of toluene with propene.{{cite encyclopedia|title=Alkylation|first1=Bipin V.|last1=Vora|first2=Joseph A.|last2=Kocal|first3=Paul T.|last3=Barger|first4=Robert J.|last4=Schmidt|first5=James A.|last5=Johnson|year=2003|encyclopedia=Kirk‐Othmer Encyclopedia of Chemical Technology|doi=10.1002/0471238961.0112112508011313.a01.pub2|isbn=0471238961}}
Related compounds
It is a constituent of a number of essential oils, most commonly the oil of cumin and thyme. Significant amounts are formed in sulfite pulping process from the wood terpenes.
p-Cymene is a common ligand for ruthenium. The parent compound is [(η6-cymene)RuCl2]2. This half-sandwich compound is prepared by the reaction of ruthenium trichloride with the terpene α-phellandrene. The osmium complex is also known.{{cite journal |first1=M. A. |last1=Bennett |first2=T.-N. |last2=Huang |first3=T. W. |last3=Matheson |first4=A. K. |last4=Smith | title = (η6-Hexamethylbenzene)Ruthenium Complexes | journal = Inorganic Syntheses | year = 1982 | volume = 21 | pages = 74–78 | doi = 10.1002/9780470132524.ch16|isbn=9780470132524 }}
Hydrogenation gives the saturated derivative p-menthane.
References
{{DEFAULTSORT:Cymene, p-}}
{{Hydrocarbons}}