Benzene

Benzene is an organic compound with the formula C6H6.
It’s a planar molecule consisting of a ring of six carbon atoms, each of which is also bonded to a hydrogen atom.
Benzene’s structure can be represented as a hexagon with a circle inside it to denote the pi system of electrons.

Benzene’s stability and unique properties are attributed to its resonating structure or delocalised model.
The six pi electrons are shared equally among the carbon atoms, creating a system of delocalised electrons above and below the plane of the molecule.
This delocalisation leads to extraordinary stability, a phenomenon referred to as aromatic stability.

Benzene tends to undergo substitution reactions rather than addition, preserving its aromatic system which accounts for its stability.
For example, in nitration of benzene, a nitro group (-NO2) replaces one of the hydrogen atoms in the benzene ring.
Benzene can also undergo halogenation (the substitution of hydrogen with a halogen), sulfonation (the addition of a sulfonic acid group), and alkylation (the addition of an alkyl group) among other reactions.

Benzene and its derivatives are vital for the synthesis of many dyes.
Azo dyes, for instance, often involve coupling reactions with benzene derivatives.
Importantly, the extended delocalisation of pi electrons in benzene rings is responsible for the colour properties of many organic compounds.

Although benzene is a useful compound in chemistry, it’s recognised as a carcinogen and may cause health issues
Therefore, handling benzene demands utmost care, usage of personal protective equipment and good ventilation.

The resonance or delocalised model of benzene accounts for its unusual stability and reaction behaviour.
Substitution reactions are predominant in benzene due to its attempt to maintain aromatic stability.
Benzene’s conjugated pi system is essential to the colour properties of many organic compounds and dyes.
Handling benzene requires stringent safety precautions due to its carcinogenic nature.