[davidenarb]

Hi Chemists!!

In the bellow figure, we have a resonance structure of a moderate activator.

From the arrows of the resonance structures, it seems that that moderate activator is an electron-withdrawing group since an electron density is pointing away from the ring withdrawing thereby an electron density from the ring, so I would like to understand how it can be an activator!!?

Thank you

[discodermolide]

Try pushing the O lone pair the other way, in towards the ring and draw the resonance structures.

[davidenarb]

Try pushing the O lone pair the other way, in towards the ring and draw the resonance structures.

In that way, yes I do agree that it's an activator, but how can a lone pair of resonance can have two directions of electron density?

[discodermolide]

What you have drawn is just another one of the possible resonance structures. Move the aromatic protons towards the positive oxygen, leaving a + charge on the ring carbon. See what you get.

[davidenarb]

What you have drawn is just another one of the possible resonance structures. Move the aromatic protons towards the positive oxygen, leaving a + charge on the ring carbon. See what you get.

so I am curious to know the difference between a strong activator and moderate activator??