Edexcel A Level Chemistry:复习笔记7.4.4 Phenol

Reactions of the aromatic ring in phenols

• Phenols react more readily with electrophiles compared to benzene
• This is because one of the lone pairs of electrons on the oxygen atom in -OH overlaps with the π bonding system
• This increases the electron density of the benzene ring making it more susceptible to electrophilic attack
• The -OH group in phenols is activating and directs incoming electrophiles to the 2, 4, and 6 positions

Bromination

• Phenols also undergo electrophilic substitution reactions when reacted with bromine water at room temperature
• Phenol decolourises the orange bromine solution to form a white precipitate of 2,4,6-tribromophenol
• This is also known as the bromination of phenol

Phenols undergo bromination when reacted with bromine water at room temperature