Those organic compounds which contain cyclic planar structure (benzene ring or other) and have 4n+2 number of delocalized pi electrons are called aromatic compounds. In other words, those cyclic compounds which obey Huckles rule are called aromatic compounds. Some of the examples of aromatic compounds are benzene, naphthalene, azulene, antracene etc.
Characteristics of Aromatic compounds:
- These are cyclic compounds containing five six or seven numbered ring.
- Aromatic compounds are highly unsaturated.
- Aromatic compounds produces shooty flames when burnt.
- They have sweet smell.
- Aromatic compounds give special reactions like Fridel Craft Reaction, Perkin’s Reaction, Reimer-Tiemann reaction etc.
- Aromatic compounds follows Huckle’s rule.
Aromaticity: The property of organic compounds that have at least one conjugated ring of alternate single and double bonds, and exhibit extreme stability.
Huckles Rule: It states that any organic compound that has cyclic planar structure with a system of delocalized electron can be aromatic if it has 4n+2 number of delocalized pi electrons. This 4n+2 is often called as magic number. So any organic ring system with magic number of delocalized pi electrons can be aromatic and can show aromaticity.