# Paracetamol: does oxygen participate in the delocalization of p-orbitals

I'm analyzing the molecular structure of paracetamol and one of the things I have to do is to make a commentary about the delocalization of p-orbitals in this compound. Well I know that in the cyclic structure of carbons there is indeed delocalization of p-orbitals. I wonder if the oxygen that makes the double covalent bond participates in this delocalization or not... Can you help me figuring this out?

Also if only the 6 carbons have the delocalization of p-orbitals then we will have 6 molecular orbitals $\pi$ delocalized and so we will have 3 $\pi$ bonding orbitals full 3 $\pi^*$ antibonding orbitals empty, right? I saw this on a book (about other compound) and I want to know if this is related to the fact that molecular orbitals number needs to be the same as atomic orbitals number? But for example, if we had 8 $\pi$ molecular orbitals would we have 4 bonding and 4 antibonding? Does that happen?

• Which oxygen you're talking about? – Mithoron Jun 21 '16 at 21:36
• Right! I forgot to mention it. I meant the one that makes the double bond of course. Sorry, thank for spotting it – Granger Obliviate Jun 21 '16 at 21:38
• You will have one large pi system including the phenyl ring, the phenolic oxygen, the amide nitrogen, carbon and oxygen. So basically, all non-hydrogen atoms except for the terminal methyl group’s carbon. I’ll leave the formal answer to somebody else who feels like drawing/calculating/whatevering. – Jan Jun 22 '16 at 18:06