KEKULE

• WHAT DID KEKULE PROPOSE BENZENE WAS?

  cyclic triene
• WHAT WERE THE ISSUES WITH BENZENE'S MODEL?

  1. Cyclic triene should show addition reactions, benzene rarely does
  2. Cyclic triene should give rise to two isomeric di-substituted compounds
  3. Hexagon would not be symmetrical as C=C shorter than C-C, but the X-ray diffraction of benzene shows perfect hexagon
• HOW DID KEKULE ATTEMPT TO SOLVE THE ISSUE OF ISOMERS?

  • rapid equilibrium model
  • location of C=C changes before any attracted molecules have time to react
  • theory evolved into resonance hybrids