P-Cymene

Cymene

Names
IUPAC name 1-methyl-4-(1-methylethyl)benzene
Other names 4-isopropyltoluene
Identifiers
CAS Number	99-87-6
3D model (JSmol)	Interactive image
ECHA InfoCard	100.002.542
EC Number	202-796-7
PubChem CID	7463
CompTox Dashboard (EPA)	DTXSID3026645
InChI InChI=1/C10H14/c1-8(2)10-6-4-9 (3)5-7-10/h4-8H,1-3H3
SMILES CC(C)c1ccc(C)cc1
Properties
Chemical formula	C10H14
Molar mass	134.21 g/mol
Appearance	Colourless liquid
Density	0.857 g/cm3
Melting point	-68°C
Boiling point	177°C
Solubility in water	Negligible
Hazards
Flash point	47°C
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Cymene, or p-cymene, is a naturally occurring aromatic organic compound. It is classified as a hydrocarbon related to a monoterpene. Its structure consists of a benzene ring para-substituted with a methyl group and an isopropyl group. It is insoluble in water, but miscible with ethanol and ether.

Cymene is a constituent of a number of essential oils, most commonly the oil of cumin and thyme.

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.

Cymene is a common ligand for ruthenium. The parent compound is [(η⁶-cymene)MCl₂]₂. This half-sandwich compound is prepared by the reaction of ruthenium trichloride with the terpene α-phellandrene. The osmium complex is also known.^[1]