Cyclohexene
A six-membered ring containing one carbon–carbon double bond.
- Formula
- C6H10
- Functional group
- Alkenes
- Molar mass
- 82.14 g/mol
- Also known as
- Tetrahydrobenzene, Cyclohex-1-ene, Benzene tetrahydride, 1,2,3,4-Tetrahydrobenzene, Benzenetetrahydride, Hexanaphthylene
Overview
A six-membered ring containing one carbon–carbon double bond.
The alkene contributes a localized addition site within the ring. Bromination through a halonium intermediate favours anti addition, giving trans-1,2-dibromocyclohexane. The ring and double bond each contribute one degree of unsaturation; neither makes this molecule aromatic.
Identifiers
- Formula
- C6H10
- Functional group
- Alkenes
- Molar mass
- 82.14 g/mol
- Also known as
- Tetrahydrobenzene, Cyclohex-1-ene, Benzene tetrahydride, 1,2,3,4-Tetrahydrobenzene, Benzenetetrahydride, Hexanaphthylene
Chemical identifiers
- SMILES
- C1CCC=CC1
- InChI
- InChI=1S/C6H10/c1-2-4-6-5-3-1/h1-2H,3-6H2
- PubChem CID
- 8079
Properties
- Melting Point
- -103.5 °C
- Boiling Point
- 83 °C at 760 mm Hg
- Relative density (water = 1)
- Relative density (water = 1): 0.81
- Water solubility
- In water, 213 mg/L at 25 °C
Diagnostic tests
Bromine addition test
- Reagent
- prepared dilute bromine solution in hexane
- Conditions
- Small-scale test away from strong light, using the reference comparison.
- Positive observation
- Bromine colour disappears rapidly.
- Negative observation
- The matched saturated-hydrocarbon control retains colour initially.
- Interpretation
- Consumption of bromine is consistent with addition at the double bond.
- Scope
- Expected positive for cyclohexene.
- Limitations
- Bromine is consumed by several reactive compounds; product analyses are listed separately.
- Evidence
- reference experiment
Related compounds
- Alkenes
A six-membered ring containing one carbon–carbon double bond.
Connected reactions
- Dehydration: Cyclohexanol → Cyclohexene
Cyclohexanol gives cyclohexene through dehydration.
References
- PubChem Compound Summary: Cyclohexene (CID 8079)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- OpenStax Organic Chemistry: Halogenation of alkenes: addition of X2John McMurry · OpenStax · 2023
Supports the qualitative structure and reactivity context; identity and numerical measurements retain their original references.
- Hazardous Substances Data Bank (HSDB): Cyclohexene — melting pointHazardous Substances Data Bank (HSDB)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/8079#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 475
- Hazardous Substances Data Bank (HSDB): Cyclohexene — boiling pointHazardous Substances Data Bank (HSDB)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/8079#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 475
- ILO-WHO International Chemical Safety Cards (ICSCs): Cyclohexene — densityILO-WHO International Chemical Safety Cards (ICSCs)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/8079#section=Density. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred.
- Hazardous Substances Data Bank (HSDB): Cyclohexene — solubilityHazardous Substances Data Bank (HSDB)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/8079#section=Solubility. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Yalkowsky, S.H., He, Yan., Handbook of Aqueous Solubility Data: An Extensive Compilation of Aqueous Solubility Data for Organic Compounds Extracted from the AQUASOL dATAbASE. CRC Press LLC, Boca Raton, FL. 2003., p. 283
- Testing for unsaturation with bromine on a microscaleRoyal Society of Chemistry · RSC Education
Source-supported qualitative reference observations.