Zusammenfassung der Ressource
Benzene
- Kekule's structure
- Alternate single and double bonds
- FOR - This can be hydrogenated to
form cyclohexane
- C6H6+3H2 -- C6H12
- AGAINST - Only three isomers of
dichlorobenzene but kekule
predicted 4
- AGAINST - Should turn bromine
water colourless as it is
unsaturated but it doesn't
- Today's benzene
- Planar ring of 6 C's with 1.5 bonds between them
and a ring of delocalized electrons
above and below
- Stability of benzene
- Cyclohexene - cyclohexane has enthalpy change -120
- Kekule's value should be 3 times this = -360
- Actually -208 - a lot less
- More stale than predicted due
to the rings of delocalized
electrons
- Nitro compounds from benzene
- Electron ring create and area of high
electron density - can be attacked by
nucleophlies
- HNO3+2H2SO4 = NO2++H3O++2HSO4-
- Made in a two step process
- Alfred Noble
- C6H5NH2 = TNT
- Made through hydration of nitration
- Aromatic ketones from benzene
- Friedel-Crafts acylation
- CH3COCl+AlCl3 = CH3C+0+AlCl4-