4.7 Aromatic compounds

What is an aromatic compound

Aromatic compounds are compounds that contain cyclical arrangements of alternating double and single bonds.

• They can have very different properties compared to Aliphatic and Alicyclic compounds

What are Aliphatic and Alicyclic compounds

• Aliphatic compounds are linear or branched compounds (Alkanes, Alkenes, Alkynes)

• Alicyclic compounds are cyclic compounds (cyclic hydrocarbons)

What is Benzene

Benzene is C₆H₆. To meet the bonding needs of each carbon in its chain, it forms an aromatic structure (cyclohex-1,3,5-triene).

• Because electrons are constantly in movement, there are many resonance structures for benzene. Therefore, the compound is often drawn as a hexagon with a circle in the middle to indicate the average bond value.

What is the bond length of a Benzene bond

The average bond length of a benzene bond is 1.5 bonds per carbon, which sits in between the length of a single and double bond.

• The greater the # of bonds, the shorter the bond length, as pi bonds must be close together to form a bond.

How to name compounds that include a benzene

• if the benzene is the parent chain, it keeps its name: benzene

• if the benzene is the functional group, it gains the name phenyl.