Question

I was able to figure out that the structure of this compound was a benzene ring with 2 equivalent trimethyl groups to give the 18H singlet. Another non-equivalent methyl group to give the 3H singlet. The singlet (integration of 1) from a hydroxyl group and the singlet at approx 6.9 ppm from hydrogens attached to the benzene. However, when assembling the molecule, I found that my structure was incorrect as it was not symmetrical, why is it a requirement that this molecule has to be symmetrical?

Answer 1

The symmetry in benzene and its derivatives stems from the resonance structure of benzene, where the delocalized electrons result in all carbon-carbon bonds being of equal length.

Step-by-step explanation:

To address the student's question about the symmetry in benzene derivatives, it is essential to understand the resonance structure of benzene. Benzene is a cyclic, hexagonal, planar molecule with sp² hybridized carbon atoms; each bonded to one hydrogen atom.

The unique bonding structure of benzene is characterized by alternating single and double C-C bonds, which provides exceptional stability to this molecule and circumvents reactivity akin to typical alkenes. Thus, benzene does not react as one might expect based on its unsaturated structure.