Explain the difference in reactivity between benzene and phenol with bromine?
Phenol reacts with bromine at room temperature with no catalyst as the hydroxyl group activates the ring by donating a pi electron. This donated electron increases the electron density of the ring hence allowing it to polarise a Br2 molecule and create a partially positive Br which can undergo nucleophilic attack.Benzene does not react with bromine on its own and requires a halogen carrier (FeBr3). This is because the ring is not activated and can not polarise bromine on its own. The halogen carrier reacts with bromine to create a bromine cation which can more easily undergo nucleophilic attack and allows a reaction with benzene.
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