1.3 Aromatic Hydrocarbons (Benzene Rings)

 Hydrocarbons

  • Benzene: alternating double bonds in a cyclohexane. Drawn as a circle inside a hexane.
Naming Aromatic Compounds
  1. Use the benzene ring as the parent chain

   
   1. “benzene” becomes the root
   2. other rules remain the same

      
      1. Use this method when the substituent is simple

  1. Name the benzene ring as the substituent with the name “phenyl”

   
   1. Use this method when the substituent is complex

 Ways of Naming

Special Cases
  • Orthodimethylbenzene
  • Metadimethylbenzene
  • Paradimethylbenzene

 TOMP

Properties of Aromatic Hydrocarbons
  • Liquids of crystalline solids at room temperature
  • Non-polar
  • Insoluble in water
Reactions of Aromatic Hydrocarbons
  • Aromatic hydrocarbons unlike alkanes are unsaturated, but they undergo ^^substitution reactions like alkanes.^^
  • This is because the bonds are not alternating single-double bonds like in the structural diagram, but ^^equal bonds in resonance.^^
Halogenation

 Halogenation requires a catalyst such as FeCl3

Nitration

 Nitration requires Requires a catalyst such as H2SO4

Alkylation

 Alkylation requires an alkyl halide and a catalyst such as AlCl3