Question

Why the given compound is non-aromatic?

Answer 1

What does the Huckel criterion say? It has been explained to you in a recent, previous answer.

Explanation:

You gots the anion of a 7-membered ring....how many `pi-"electrons"`?

On the other hand, `C_7H_7^+`, so-called tropylium ion, that derives from `"1,3,5-cycloheptatriene"`, DOES fill the Huckel criterion, and this has an extensive coordination chemistry.

In tropylium ion, the `pi-"electrons"` are conjugated around a planar ring....is the Huckel criterion fulfilled?

ANd what would happen if we REDUCED `"1,3,5,7-cyclooctatetraene"` by 2 electrons, ?

And if you do not know the answer to the last question, look up the structure of `"uranocene"`.