Aromatic Compounds and Their Derivatives
Alkyl compounds where made from straight chains and cyclics of straight chains. Aromatic compounds are made from benzene and its derivatives. It is a six-membered ring with three double bonds. The double bonds alternate and move around the ring which make them hard to attack and break. For this reason benzene is a very stable molecule. A short form version of the ring consists of a hexagon indicating the six-membered C ring and a circle in the middle indicating the alternating three double bonds.
Benzene  C6H6
     --------    resonates   -------->
The alternating double bonds fluctuate or resonate around the ring. The resonating bonds are difficult to attack and this makes the benzene ring structure very stable. Substitutions can be made to each of the hydrogens on the ring but breaking the ring itself  is difficult. The short form version of the above structure is below.
    Benzene short form
Special Compound Derivatives of Benzene
There are two ways to name benzene ring compounds. The C's on the ring can be numbered in order starting from the most important add-on radical or we can use the ortho, meta, para system.  See the diagram below for the placement of these names.
  Benzene "ortho", "meta" and "para" naming convention
The following molecules are all derivatives of benzene.  Since they are very common these are all used as parent names from which other more complex names can be derived.
Phenol Toluene Benzoic acid Benzaldehyde


Nitrobenzene Styrene Aniline para-Cresol (creosote)
There are of course, many more.

Go to the Aromatics Worksheet