Question

What is the difference between anti-aromatic and non aromatic compounds?

Answer 1

Non aromatic compounds fullfil none of the requirements for aromaticity. Antiaromatic compounds have some of the requirements but not in terms of electron numbers.

Explanation:

Aromatic compounds are cyclic and have a `pi` electron system that contains (4n+2) `pi` electrons. The number of electrons allows delocalisation of the electron cloud which lowers the overall energy of the system and increases stability.

Anti-aromatic compounds are also cyclic, and each component carbon atom also exhibits `pi` bonidng, has a but actually have a higher energy due to the presence of (4n) `pi` electrons - the ring current observed in these compounds is paramagnetic, rather than diamagnetic.

Non-aromatic compounds are either not cyclic, or are cyclic without being "flat" rings (e.g. `sp^3` hybridised carbons, such as cyclohexane).