Aromatic Chemistry Flashcards
What is an Arene/aromatic compound
A molecule that contains a benzene ring.
Name The two benzene mechanisms
Friedel Crafts Acylation, Nitration
What is the Purpose of the Friedel Crafts Acylation ?
Acyl group added to Benzene molecule
-To weaken the benzene molecule so it can be modified to make useful products.
Describe Benzene in terms of structure
Cyclic, planar molecule
Describe Benzene in terms of bonding and electrons
Each carbon atom has four electrons
- 2 Electrons bonded to 2 other carbon
- 1 Electron bonded to 1 Hydrogen atom
- 1 lone in p orbital which stick above and below the ring.
What do the p orbitals combine to form?
A delocalised ring of electrons
What did Kekule think about the Benzene structure ?
-Consisted of alternating double and single bonds
What proved Kekules theory wrong
- All bonds in the benzene have the same length
-Lower enthalpy of hydrogenation that expected
-Unreactive with bromine water
Why is Benzene stable?
Due to its delocalised ring of electrons.
What are molecule (c6H5) with a functional group called?
Phenyl
Why are electrophiles attracted to benzene?
Due to its high electron density in the delocalised ring of electrons.
What type of reactions do Arenes undergo?
Electrophilic substitution - as electrophilic addition would disrupt the stable ring of electrons.
Requirements of Friedel Crafts Acylation
Powerful electrophile.
-For step 2 - carry out under reflux
Steps of F.C Acylation
-React Acyl with Chlorine carrier to form more powerful electrophile
-React Electrophile with benzene to form less stable phenylketone
Why is AlCl3 a catalyst in the F.C Acylation
It reforms- not used up
