Is Tropolone Aromatic Despite Its Unusual Structure?

[themonk]

I understand the rules of aromaticity, but I do not understand why Tropolone is aromatic. The main reason is because I thought all the atoms in the ring have to have p-orbitals. How does the C connected the oxygen with a double bond have a p-orbital? Have to do with the resonance (that's my main guess)?

It passes Hückel's rule with 6e- pi electrons and also passes other criteria.

 

[DrDu]

Whether a C-atom "has" a p-orbital or not is a question of definition. How would you test experimentally if Tropolone is aromatic because you are so sure about it?

 

[DDTea]

You touched on the Hueckel rule for aromaticity but not the full definition: 4n + 2 pi electrons in a conjugated, cyclic system. Yes, this does meet that criteria.

Why do you think the carbonyl C does not have a p-orbital? There is a pi bond between C and O, so how can it not have p orbital? Can you explain more clearly what you think the problem is?

 

[themonk]

Whether a C-atom "has" a p-orbital or not is a question of definition. How would you test experimentally if Tropolone is aromatic because you are so sure about it?

You can do NMR Spectronomy for a good result to see if it is Aromatic.

Why do you think the carbonyl C does not have a p-orbital? There is a pi bond between C and O, so how can it not have p orbital? Can you explain more clearly what you think the problem is?

I understand now that C and O have a pi bond because they have a double bond between each other. I just wasn't thinking because it was late. So then there are pi bonds on all the Carbons, creating a continuous lobed structure. I was just was not thinking enough about how pi bonds form.

Thanks for your help DrDu and DDTea.