chapter  11
18 Pages

Radical Substitution Reactions

WithMichael Edenborough

This chapter deals with the radical species that are electrically neutral. One of the most important features of free radical chemistry is that the reactions are not affected by the normal variations in reaction conditions, such as a change in the polarity of the solvent or the acid/base characteristics of the reagents, except insofar as these changes will favour or disfavour competing ionic reactions. Radicals have an unpaired electron and are usually electrically neutral. Accordingly, radical substitution reactions tend not to be affected by those factors, such as solvent polarity, that affect mechanisms involving charged species, such as nucleophilic or electrophilic substitution. In the photochlorination reaction, the chlorine radical abstracted a hydrogen atom, and so produced a carbon radical. In the case of methane, there was only one type of hydrogen that the chlorine radical could attack, but in a larger alkane there is often a choice.