Why aren't all bond lengths equal in cyclobutadiene?

Question

even when there is a possibility of conjugation why aren't bond lengths equal?

Could you cite where you found that the bond lengths are not equal? — A.K., Mar 19 '19 at 13:20
Heard of anti aromaticity it destabilizes a cyclic compound so to prevent it no conjugation — Aditya Garg, Mar 19 '19 at 13:20
Your title does not match your question. All *double* bonds are equal all right. — Ivan Neretin, Mar 19 '19 at 14:09
Possible duplicate of Resonance structure of cyclobutadiene? — Mithoron, Mar 19 '19 at 16:47

score 4 · Answer 1 · answered Mar 19 '19 at 13:25

Anti-aromatic compounds have no delocalization of electrons hence no resonance. To check aromatic character we use huckel's rule of (4n+2)π e- present in a conjugated closed loop. An anti aromatic compound would have only 4nπ electrons which is the case with above mentioned compound . Hence the bond lengths are different. enter image description here

Why aren't all bond lengths equal in cyclobutadiene?

1 Answers1