Aromatic Functional Group

The aromatic hydrocarbons are a fourth class of organic compounds with only carbon and hydrogen. We recognize the alkanes, alkenes and the alkynes from their formulas which follow the general formula as shown below,

Hydrocarbon

Formula

alkanes

CnH2n+2

alkenes

CnH2n

alkynes

CnH2n-2

The aromatics are a fourth group,

Hydrocarbon

Formula

aromatic

CnHn

The only member of the aromatic group we will spend time on is benzene, C6H6. It looks like,

Functional Group

Ball-and-stick

Lewis Structure

aromatic (benzene)

Recognizing the aromatic group consists of finding the six-membered ring of carbon atoms. Although the ball-and-stick model above does not clearly show it the benzene ring is planar.

Functional Group

Ball-and-stick

Lewis Structure

aromatic (benzene)

Benzene is a liquid at room temperature and is an important solvent because organic compounds are more soluble in it than in water.

Lets look at some compounds that contain the aromatic benzene (benzyl) group.

Compound

Ball-and-Stick

Lewis Structure

Toluene (methyl benzene)

Phenol

Styrene

Phenol is interesting as it has an alcohol functional group as well as the aromatic functional group.

Return to man functional group page.