Cyclohexene, Benzene and Phenol - Reactivity and structure
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?- Created by: Danny
- Created on: 07-10-12 18:10
Three Flaws in Kekules structure of Benzene:
- Low Reactivity (3 Double bonds should of made Benzene reactive/unstable however it is a stable molecule)
- Lower Enthalpy (Expected Enthalpy = -360kjmol-1 -- Actual Enthalpy
- 208kjmol-3) - Carbon-Carbon bond lengths are not symmetrical as stated (x-ray diffraction proved this)
Reactions Under normal Conditions:
Benzene will not:
- De-colourise Bromine water
- React with strong acids
- React with halogens
Cyclohexene will:
- Decolourise Bromine water
- React with strong acids
- React with halogens
Features of Benzene:
Benzene is a cyclic hydrocarbon with a structural formula of C6H6, the shape around each carbon is trigonal planar which has a bond angle of 120 degrees.
The electrons in the P-orbitals overlap, this results in a ring of electron density above and below the plane of Carbon atoms. This produces a 'pi-cloud' where one carbon atom contributes one electron forming a delocalised system of six electrons.
To preserve stability, Benzene takes part in Electrophilic substitution reactions (Electrophile substitutes an atom)
Electrophile: is an atom that is attracted to an electron rich centre which accepts a pair of electrons forming a dative covelant bond.
Delocalised: Electrons are shared between more than two atoms.
Nitrification of Benzene:
Reagents required:
- Concentrated HNO3
- Concentrated H2SO4
Conditions Required:
- 50 degrees Celsius
- Reflux
Bromination of Benzene:
- Benzene is too stable to…
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