INTRODUCTION

•	The word aromatic can be used to describe fragrant substances such as benzaldehyde (from cherries, almonds), and toluene (from Tolu balsam).

•	However, in the early nineteenth century such substances were discovered to behave in a different chemical manner from other organic compounds. Thus, in chemistry, the term aromatic is now used to refer to benzene and it’s structural relatives.

•	The Cambridge Structural Database can be used to explore the structural requirements for aromaticity. By investigating the structure of such compounds we can explain their special stability.