question_answer 93)

  In Kolbe's reaction, instead of phenol, phenoxide ion is treated with carbon dioxide. Why ?

Answer:

                  Due to greater ability of ion (than OH group) to donate electrons to the benzene ring, phenoxide ion is more reactive than phenol towards electrophilic aromatic substitution reactions. In other words, phenoxide ion being a stronger, nucleophile reacts easily with the weak electrophile carbon dioxide to bring about the 4 electrophilic substitution reaction.