Chapter 23, Problem 23.5YT

Interpretation Introduction

Interpretation:

The resonance form of para arenium ion intermediate produced during nitration of toluene that is responsible for making this intermediate more stable than the meta arenium ion intermediate is to be identified.

Concept introduction:

The para arenium ion intermediate formed during the nitration of toluene is more stable than the meta arenium ion intermediate. This is because out of the three resonance forms of para arenium ion intermediate, one has positive charge at the substituted carbon (adjacent to methyl group) whereas in meta arenium ion intermediate, out of the three resonance forms, the positive charge is at the unsubstituted carbon. In meta arenium ion intermediate, there is no contribution of methyl group for the carbocation stabilization whereas in para arenium ion intermediate, methyl group stabilizes the positive charge at the adjacent carbon, making it more stable than the meta arenium ion intermediate.