Aromatic compounds are hydrocarbons that contain a cyclic (ring-shaped) structure with pi bonds in resonance, which means that the electrons represented by the double bonds in the Lewis diagram are actually distributed evenly around the ring, increasing the molecules stability. Aromatic rings are very stable and do not break apart easily. Organic compounds that are not aromatic are classified as aliphatic compounds. The term "aromaticity" is historically related to the concept of having an aroma, but it is a distinct property from that meaning.
Aromatic compounds serve as the basis for many drugs, antiseptics, explosives, solvents, and plastics (e.g., polyesters and polystyrene). The two simplest unsaturated compounds, ethylene (ethene) and acetylene, are not aromatic.
A natural aroma chemical is a chemical compound used to enhance scents and fragrances, while synthetic aroma chemicals are formulated in a laboratory to resemble aromas found in nature. Aroma chemicals can be used to infuse fragrance into various products with their simple, pure, and manageable aroma.
