Question

Why is benzene extra ordinarily stable though it contains three double bonds?

Answer 1

Benzene is a hybrid of resonating structures given as:

All six carbon atoms in benzene are sp² hybridized. The two sp² hybrid orbitals of each carbon atom overlap with the sp² hybrid orbitals of adjacent carbon atoms to form six sigma bonds in the hexagonal plane. The remaining sp² hybrid orbital on each carbon atom overlaps with the s-orbital of hydrogen to form six sigma C-H bonds. The remaining unhybridizedp-orbital of carbon atoms has the possibility of forming three π bonds by the lateral overlap of \(C_1-C_2,\ C_3-C_4,\ C_5-C_6\  \text {or}\  C_4-C_5,\ C_6-C_1\).

The six \(\pi's\) are delocalized and can move freely about the six carbon nuclei. Even after the presence of three double bonds, these delocalized \(\pi\)-electrons stabilize benzene.