The Effect of Solvent Polarity on Chemical Reactions

The main principles and concepts of the effect of solvent polarity on chemical reactions and equilibria are outlined in the following sections. However, this is a vast subject area beyond the scope of this work and the interested reader will find a detailed discussion elsewhere [1], 

By contrast, in an Sn2 reaction, a charged nucleophile reacts with an uncharged substrate to form a transition state in which the negative charge of the nucleophile 

The direction and extent of the effect of solvent polarity on reaction rates of nucleophilic substitution reactions are summarized by the Hughes-Ingold rules, shown in Table 1.9 [26], These rules do not account for the entropic effects or any specific solvent-solute interactions such as H-bonding, which may lead to extra stabilization of reactants or transition states [27]. 

Reaction Reactants Transition state Change in charge distribution Effect of increasing solvent polarity Size of effect 

---