Illustrated Glossary of Organic Chemistry

Aromaticity: Special molecular stability associated with a closed loop of adjacent, parallel, overlapping p orbitals containing 4n+2 pi electrons (n = 0, 1, 2, 3, etc.; Huckel's rule).


 



 

Benzene
  
Furan
  
Cyclobutadiene
  
Cyclooctatetraene
Aromatic (n = 1)
Antiaromatic (n =1/2)

Nonaromatic (n = 3/2)