Cycloheptene
Chemical compound
From Wikipedia, the free encyclopedia
Cycloheptene is a 7-membered cycloalkene with a flash point of −6.7 °C. It is a raw material in organic chemistry and a monomer in polymer synthesis.[not in body] Cycloheptene can exist as either the cis- or the trans-isomer.
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| Names | |
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| Preferred IUPAC name
Cycloheptene | |
| Other names
cis-Cycloheptene | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.010.056 |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C7H12 | |
| Molar mass | 96.17 g/mol |
| Density | 0.824 g/cm3 |
| Boiling point | 112 to 114.7 °C (233.6 to 238.5 °F; 385.1 to 387.8 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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trans-Cycloheptene
Under normal conditions, the cycloheptene double bond forms the cis isomer. However, the unstable, anti-Bredt, trans isomer is an accessible reactive intermediate. Methyl benzoate catalyzes singlet photosensitization; irradiating cis-cycloheptene and it with ultraviolet light at −35 °C produces a detectible trans-cycloheptene population.[2]
The trans isomer is very strained,[3] and the unsaturated carbons are partly pyramidal. The pyramidalization angle is estimated at 37° and the p orbital misalignment 30.1°. The isomer decomposes facily through a dimolecular, diradical pathway, even at temperatures too low for double-bond rotation.[2]