Aromatic Chemistry

Benzene

Benzene

Structure

Benzene is a cyclic hydrocarbon; it contains six carbon atoms and six hydrogen atoms. It was originally thought to be a ring composed of six carbon atoms with alternate single and double bonds. However, closer analysis of the molecule has revealed that all the bonds are of the same length (0.142nm), intermediate between single and double bonds. Therefore, it is now believed to contain delocalised electrons in six overlapping orbitals instead. This can be represented as either this:

Or with the delocalised electrons as a circle within the hexagonal ring:

However, it is usually represented by its skeletal formula:

In benzene all the electrons are delocalised completely. The angle between the atoms is 120