Benzene and Its Derivatives

1
Chapter 13

• Benzene and Its Derivatives

2
Structure

• Aliphatic alkanes, alkenes and alkynes
• Aromatic benzene ring
• What is benzene? C6H6
• Resonance structure
• Very stable

3
Nomenclature

• Monosubstituted
• chlorobenzene
• Common names
• Phenol (-OH)
• Toluene (-CH3)
• Aniline (-NH2)
• Benzaldehyde (-CHO)
• Benzoic acid (-COOH)

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Phenyl and Benzyl Groups

• Phenyl (fennel) group
• Benzyl group

5
Nomenclature

• Disubstituted
• ortho (1,2 substituted)
• meta (1,3 substituted)
• para (1,4 substituted)
• ortho-, meta- and para- xylene (dimethylbenzene)

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Nomenclature

• Polysubstituted (number with smallest sum)
• 2,4,6-trinitrotoluene (TNT)
• 2,4,6-tribromophenol
• 2-bromo-1-ethyl-4-nitrobenzene

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Physical Properties

• same as alkanes

8
Chemical Properties

• Combustion (characteristic black smoke)
• Aromatic substitution
• Halogenation (-X)
• Nitration (-NO2)
• Sulfonation (-SO3H)

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Phenols Physical Properties

• Acid-Base reactions
• Ka 10-10 very weak acids
• Used as disinfectants (carbolic acid)
• Lysol o-phenylphenol