15 P Classify each substituent as ele... [FREE SOLUTION]

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Chapter 18: 15 P (page 694)

Classify each substituent as electron donating or electron withdrawing.

Short Answer

Expert verified

a. Electron donating substituents.

b. Electron withdrawing substituents.

c. Electron donating substituents.

Step by step solution

Substituents

The substituents (placed on the ring) can have an electron attracting tendency or electron-donating tendency. The nature of the substituents depends upon the atoms present in the substituents.

Electron donating and electron-withdrawing groups

The electron-withdrawing substituents have an electronegative atom that attracts electrons towards themselves. Therefore, the positive charge delocalizes on the ring.

The electron-donating substituents have an electropositive atom which gives electrons to the ring. Therefore, the negative charge delocalizes on the ring.

Explanation

a. The ${CH}_{3} O$ group is an electron-withdrawing substituent but the oxygen has lone pair of electrons which is donated to the ring. Therefore, here ${CH}_{3} O$ group is an electron-donating substituent.

b. The iodine group is an electron-withdrawing substituent because iodine is an electronegative atom.

c. The ${({CH}_{3})}_{3} C^{-}$ group is an electron-donating substituent because carbon is an electropositive atom.