I am quoting a rule on resonance from Organic Chemistry by T.W. Graham Solomons, Craig B. Fryhle, 12th edition, page 25.
- Structures in which all the atoms have a complete valence shell of electrons (i.e., the noble gas structure) are more stable.
I tried to apply to the following.
According to this rule structure 4 must be most stable. But structure 4 is not aromatic, while structure 1 is aromatic. Since aromatic species are more stable then nonaromatic species, structure 1 must be more stable.
My question is which of the structures is more stable?