Structure of Benzene
The formula of benzene is C6H6. The ring structure has alternate double and single bonds as shown in the diagrams below. According to the latest theories, benzene is in resonance between the two structural entities as shown below. Benzene has a structure that is a hybridized form of these two structures.
The hybridized structure is usually represented as shown below:
The six carbons in the benzene ring have a planar arrangement of a regular hexagon. The carbons are located at the vertices of the hexagon. The carbon-carbon bonds have the same length, and each bond angle is 120o. The hybridization is sp2. The sigma bonds are formed by the sp2 hybridized orbitals. However, the unhybridized 2p orbitals in each carbon overlap to form a cyclic pi system around the ring. The delocalization of these electrons creates the pi system in aromatic compounds. The electron cloud of the pi system occupies the regions above and below the ring as depicted in Figure 18-1.