Which of the following is not an example of benzenoid compound?

We need to identify which compound is not a benzenoid compound.

Benzenoid compounds are aromatic compounds that contain one or more benzene rings (fused or isolated). They are based on the benzene ring structure.

Non-benzenoid compounds are aromatic compounds that do not contain a benzene ring but still follow Huckel's rule of aromaticity ($$4n + 2$$ pi electrons in a planar, cyclic, conjugated system).

Let us examine each option:

Option A: Naphthalene — It consists of two fused benzene rings. It is a benzenoid compound.

Option B: Thiophene — It is a five-membered heterocyclic ring containing one sulphur atom. Its structure is:

$$C_4H_4S$$ — a five-membered ring with 6 pi electrons (4 from the two C=C double bonds and 2 from the lone pair on S). It is aromatic but does not contain a benzene ring. Therefore, thiophene is a non-benzenoid aromatic compound.

Option C: Anthracene — It consists of three linearly fused benzene rings. It is a benzenoid compound.

Option D: Phenanthrene — It consists of three angularly fused benzene rings. It is a benzenoid compound.

Therefore, the correct answer is Option B: Thiophene.