Organic molecules exist in many different forms. They are generally classified into two major groups called aliphatic organic molecules and aromatic organic molecules. Aliphatic compounds are those that contain C – C single bonds and/or double bonds. Aromatic compounds also contain these bonds but they are special that they are planar, cyclic molecules with all the C atoms having conjugated double bonds, meaning that the electron clouds of all the C atoms overlap those of the adjacent C atoms’. An electron cloud is a group of negatively charged electrons revolving around the atomic nucleus. These aromatic compounds obey Huckel’s Rule, stating that the compound must have 4n + 2π electrons in order to be classified as an aromatic compound.
The reaction of aromatic compounds is such that it is much more complex than aliphatic compounds. Because of their conjugated system, they require different kinds of chemicals, temperature regulations and much more care to assist the reactants to proceed to products. Some of the reactions involving aromatic compounds are highly useful as they can be used in synthesis of many useful drugs and other compounds.