Summary of Linear Free Energy Relationships

A large number of LFERs were discussed above many more can be found in the literature or other physical organic chemistry texts. This is especially true for Hammett-related sigma constants. For example, here is an abbreviated list of some you may encounter in the literature a , a , and j for the ionization of carboxylic acids other than benzoic acid for induc- 

Our intent here was to focus only on those that are still commonly used, and on the conceptual foundation of the methodology. The student should now be prepared to understand any new LFERs encountered in the literature. At this point, though, it may be helpful to tabulate the LFERs we have discussed in one place, so that their uses can be quickly deciphered 

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