Ion-Pairing Effects in Carbanion Reactions

This chapter explores the correlation of ion pairs with chemical behavior in a variety of carbanion systems. An understanding of the various factors determining the extent and type of ionic association is indispensible in describing ion pair effects. The chapter discusses these factors, focusing on the effect of carbanion structure. It reflects that ion pairing effects are often similar from one reaction to another, provided that the reactions are like one another in terms of the degree of charge dispersion in going from reactants to products. An understanding of the various factors determining the extent and type of ionic association is indispensible in describing ion pair effects. The chapter illustrates that the role of the counter-ion in many carbanion systems is important, sometimes even dominant, and should be studied carefully before the reactive behavior of carbanions may be evaluated. Moreover, such effects, when properly identified, may serve to probe changes in charge delocalization in carbanion reactions and may lead to a better understanding of carbanion chemistry.