Chapter 6, Problem 67P

Interpretation Introduction

Interpretation: The ion among ${\text{F}}^{-}$ , ${\text{Cl}}^{-}$ , ${\text{Br}}^{-}$ and ${\text{I}}^{-}$ that is strongest nucleophile in aqueous solution should be chosen.

Concept introduction: Bimolecular substitution or ${\text{S}}_{\text{N}}2$ proceeds via single-step mechanism. Thus it is well known as concerted mechanism. Nucleophile approaches carbon while the leaving group still departs from the rear side (opposite to leaving group). The transition state only illustrates the geometric orientation of the substrates and reagents as they pass through the maxima in the single-step mechanism.

A general ${\text{S}}_{\text{N}}2$ reaction mechanistic pathway is illustrated below: