Cyclohexene
Cyclohexene is a hydrocarbon with the formula C6H10. This cycloalkene is a colorless liquid with a sharp smell. It is an intermediate in various industrial processes. Cyclohexene is not very stable upon long term storage with exposure to light and air because it forms peroxides.
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Names | |||
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Preferred IUPAC name
Cyclohexene | |||
Other names
Tetrahydrobenzene, 1,2,3,4-Tetrahydrobenzene, Benzenetetrahydride, Cyclohex-1-ene, Hexanaphthylene, UN 2256 | |||
Identifiers | |||
3D model (JSmol) |
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906737 | |||
ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard | 100.003.462 | ||
EC Number |
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1659 | |||
PubChem CID |
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RTECS number |
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UNII | |||
CompTox Dashboard (EPA) |
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Properties | |||
C6H10 | |||
Molar mass | 82.143 g/mol | ||
Appearance | colorless liquid | ||
Odor | sweet | ||
Density | 0.8110 g/cm3 | ||
Melting point | −103.5 °C (−154.3 °F; 169.7 K) | ||
Boiling point | 82.98 °C (181.36 °F; 356.13 K) | ||
insoluble in water | |||
Solubility | miscible with organic solvents | ||
Vapor pressure | 8.93 kPa (20 °C)
11.9 kPa (25 °C) | ||
Henry's law constant (kH) |
0.022 mol·kg−1·bar−1 | ||
-57.5·10−6 cm3/mol | |||
Refractive index (nD) |
1.4465 | ||
Hazards | |||
Safety data sheet | External MSDS | ||
GHS pictograms | |||
GHS Signal word | Danger | ||
GHS hazard statements |
H225, H302, H304, H311, H411 | ||
P210, P233, P240, P241, P242, P243, P264, P270, P273, P280, P301+310, P301+312, P302+352, P303+361+353, P312, P322, P330, P331, P361, P363, P370+378, P391, P403+235, P405, P501 | |||
NFPA 704 (fire diamond) | |||
Flash point | −12 °C (10 °F; 261 K) | ||
244 °C (471 °F; 517 K) | |||
Explosive limits | 0.8–5 % | ||
Lethal dose or concentration (LD, LC): | |||
LD50 (median dose) |
1946 mg/kg (oral, rat) | ||
LCLo (lowest published) |
13,196 ppm (mouse, 2 hr)[1] | ||
NIOSH (US health exposure limits): | |||
PEL (Permissible) |
TWA 300 ppm (1015 mg/m3)[2] | ||
REL (Recommended) |
TWA 300 ppm (1015 mg/m3)[2] | ||
IDLH (Immediate danger) |
2000 ppm[2] | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |||
Infobox references | |||
Production and uses
Cyclohexene is produced by the partial hydrogenation of benzene, a process developed by the Asahi Chemical company.[3]
Reactions and uses
Benzene is converted to cyclohexylbenzene by acid-catalyzed alkylation with cyclohexene. Cyclohexylbenzene is a precursor to both phenol and cyclohexanone.[4]
Hydration of cyclohexene gives cyclohexanol, which can be dehydrogenated to give cyclohexanone, a precursor to caprolactam.[5]
The oxidative cleavage of cyclohexene gives adipic acid. Hydrogen peroxide is used as the oxidant, in the presence of a tungsten catalyst.[6]
Cyclohexene is also a precursor to maleic acid, dicyclohexyladipate, and cyclohexene oxide. Furthermore, it is used as a solvent.
Structure
Cyclohexene is most stable in a half-chair conformation,[7] unlike the preference for a chair form of cyclohexane. One basis for the cyclohexane conformational preference for a chair is that it allows each bond of the ring to adopt a staggered conformation. For cyclohexene, however, the alkene is planar, equivalent to an eclipsed conformation at that bond.
See also
- Diels-Alder reaction
- Cyclohexa-1,3-diene
- Cyclohexa-1,4-diene
External links
- International Chemical Safety Card 1054
- NIOSH Pocket Guide to Chemical Hazards. "#0167". National Institute for Occupational Safety and Health (NIOSH).
- Material Safety Data Sheet for cyclohexene
- Safety MSDS data
- Reaction of Cyclohexene with Bromine and Potassium Permanganate
- Cyclohexene synthesis
- Data sheet at inchem.org
References
- "Cyclohexene". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- NIOSH Pocket Guide to Chemical Hazards. "#0167". National Institute for Occupational Safety and Health (NIOSH).
- , Narisawa, Naoki & Katsutoshi Tanaka, "Cyclohexanol, method for producing cyclohexanol, and method for producing adipic acid"
- Plotkin, Jeffrey S. (2016-03-21). "What's New in Phenol Production?". American Chemical Society. Archived from the original on 2019-10-27. Retrieved 2018-01-02.
- Musser, Michael T. (2005). "Cyclohexanol and Cyclohexanone". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_217.
- Reed, Scott M.; Hutchison, James E. (2000). "Green Chemistry in the Organic Teaching Laboratory: An Environmentally Benign Synthesis of Adipic Acid". J. Chem. Educ. 77 (12): 1627–1629. doi:10.1021/ed077p1627.
- Jensen, Frederick R.; Bushweller, C. Hackett (1969). "Conformational preferences and interconversion barriers in cyclohexene and derivatives". J. Am. Chem. Soc. 91 (21): 5774–5782. doi:10.1021/ja01049a013.