# Strong activation of phenoxide ion compared to others

I was told that in phenoxide ion, benzene ring is very strongly activated. The order my teacher told me was phenol < amine < $$2^\circ$$-amine < $$3^\circ$$-amine < phenoxide (for activation of benzene).

Example: Reimer–Tiemann reaction happens only in sodium phenoxide

So, what is so special in phenoxide that makes it so much activating? Also, why does oxygen contribute more in resonance than nitrogen, when it is more electronegative than the latter?

• Strongly activated in respect of which property? – Waylander Apr 29 '18 at 11:35
• for example rtr happens only in sodium phenoxide – amish dua Apr 29 '18 at 11:37
• The question is probably about reactions of type electrophilic aromatic substitution. But there are possible others, e.g. redox reactions. – aventurin Apr 29 '18 at 19:23

Each given substituent ($$\ce{-OH, -NH2, -NHR, -NR2}$$) except for the phenolate ion has a lone pair. Thus, each can share it with the benzenonium nucleus to reduce the positive charge, reducing the energy of intermediate. However, phenolate ion ($$\ce{ph-O^-}$$) has full negative charge, which can neutralize benzenonium intermediate completely, to give least energy among all substituents considered here.