Aromatics

• pi electrons are delocalised electrons in benzene ring

  
• Bonding in benzene

  • each carbon has three covalent bonds
  • spare electrons in p orbital overlap to form a pi cloud
  • pi electrons in benzene ring are delocalised
• shape of benzene

  • planar
  • hexagon
  • 120 * bond angle
  • c-c bonds are equal in length
• stability in benzene

  • expected value of cyclohexatriene is -360
  • benzene is less exothermic by 152
  • benzene is more stable than cyclohexatriene