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# #pi# electrons within the ring, the compound has to have electron delocalization all throughout the ring.

Consider the structure of cyclobutene:

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

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

ANSWER: Look here.