|Preferred IUPAC name
p-Cymene (no longer recommended)
3D model (JSmol)
|Molar mass||134.21 g/mol|
|Melting point||−68 °C (−90 °F; 205 K)|
|Boiling point||177 °C (351 °F; 450 K)|
|Flash point||47 °C (117 °F; 320 K)|
|435 °C (815 °F; 708 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
p-Cymene is a naturally occurring aromatic organic compound. It is classified as an alkylbenzene related to a monoterpene. Its structure consists of a benzene ring para-substituted with a methyl group and an isopropyl group. There are two less common geometric isomers. 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. p-Cymene is insoluble in water, but miscible with ethanol and diethyl ether.
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.
Hydrogenation gives the saturated derivative p-menthane.
- Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. pp. 139, 597. ISBN 978-0-85404-182-4. doi:10.1039/9781849733069-FP001.
- M. A. Bennett; T.-N. Huang; T. W. Matheson; A. K. Smith (1982). "(η6-Hexamethylbenzene)Ruthenium Complexes". Inorganic Syntheses. 21: 74–78. doi:10.1002/9780470132524.ch16.