Is cyclobutene aromatic?

1 Answer
Jan 5, 2016

No. It has no electron delocalization at all.

One of the bare minimum requirements for aromaticity is that besides being cyclic, and having 2n+2 π electrons within the ring, the compound has to have electron delocalization all throughout the ring.

Consider the structure of cyclobutene:

That's all its π electrons can do, sadly. Even cyclobutadiene is not aromatic, though it may appear to have full electron delocalization.

CHALLENGE: Are π electrons localized or delocalized in a cyclopentadiene deprotonated at the alkyl carbon? If so, draw resonance structures for it.

ANSWER: Look here.