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Names | |||
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Systematic IUPAC name
Cyclohexa-1,4-diene
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Other names
1,4-Cyclohexadiene
1,4-Dihydrobenzene |
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Identifiers | |||
3D model (Jmol)
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Abbreviations | 1,4-CHDN | ||
1900733 | |||
ChEBI | |||
ChemSpider | |||
ECHA InfoCard | 100.010.040 | ||
EC Number | 211-043-1 | ||
1656 | |||
MeSH | 1,4-cyclohexadiene | ||
PubChem CID
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UN number | 3295 | ||
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Properties | |||
C6H8 | |||
Molar mass | 80.13 g·mol−1 | ||
Appearance | Colorless liquid | ||
Density | 0.847 g cm−3 | ||
Melting point | −50 °C; −58 °F; 223 K | ||
Boiling point | 82 °C; 179 °F; 355 K | ||
-48.7·10−6 cm3/mol | |||
Refractive index (nD)
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1.472 | ||
Thermochemistry | |||
142.2 J K−1 mol−1 | |||
Std molar
entropy (S |
189.37 J K−1 mol−1 | ||
Std enthalpy of
formation (ΔfH |
63.0-69.2 kJ mol−1 | ||
Std enthalpy of
combustion (ΔcH |
-3573.5--3567.5 kJ mol−1 | ||
Hazards | |||
GHS pictograms | |||
GHS signal word | DANGER | ||
H225, H340, H350, H373 | |||
P201, P210, P308+313 | |||
EU classification (DSD)
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F T | ||
R-phrases | R45 R46 R11 R48/20/21/22 | ||
S-phrases | S53 S45 | ||
NFPA 704 | |||
Flash point | −7 °C (19 °F; 266 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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what is ?) | (|||
Infobox references | |||
1,4-Cyclohexadiene is an organic compound with the formula C6H8. It is a colourless, flammable liquid that is of academic interest as a prototype of a large class of related compounds called terpenoids, an examples being γ-terpinene. An isomer exists of this compound, 1,3-cyclohexadiene.
In the laboratory, substituted 1,4-cyclohexadienes are synthesized by Birch reduction of related aromatic compounds using an alkali metal and a proton donor such as ammonia. In this way, over reduction to the fully saturated ring is avoided.
1,4-Cyclohexadiene and its derivatives are easily aromatized, the driving force being the formation of an aromatic ring. The conversion to an aromatic system may be used to trigger other reactions, such as the Bergman cyclization.