What are the necessary conditions for any system to be aromatic?
Solution and Explanation
A compound is said to be aromatic if it satisfies the following three conditions:
(i) It should have a planar structure.
(ii) The π-electrons of the compound are completely delocalized in the ring.
(iii) The total number of \(\pi\)-electrons present in the ring should be equal to \((4n + 2)\), where \(n = 0, 1, 2\) … etc. This is known as Huckel's rule.
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Concepts Used:
Aromatic hydrocarbon
Aromatic hydrocarbons, sometimes known as arenes, are aromatic organic molecules made up entirely of carbon and hydrogen. In aromatic compounds a benzene ring which is named after the simple aromatic chemical benzene, or a phenyl group when part of a larger structure, is the configuration of six carbon atoms.
Read More: Aromaticity
Reactions of Aromatic Hydrocarbons:
1. Aromatic Substitution Reactions
This reaction involves the replacement of one substituent on the ring of an aromatic hydrocarbon, commonly a hydrogen atom, by a different substituent group.
The common types of aromatic substitution reactions are:
- Nucleophilic aromatic substitution reactions
- Electrophilic aromatic substitution reactions
- Radical nucleophilic aromatic substitution reactions
2. Coupling Reactions
In these types of reactions, the coupling of two fragments that have a radical nature is achieved with the help of a metal catalyst