Structure elucidation with lanthanide‐induced shifts. 13—A critical evaluation of methods for obtaining bound shifts and association constants

The use of lanthanide‐induced shifts for rigorous structure analysis requires accurate values corresponding to only one of the complexes that can be formed. A combination of computational and experimental studies have been carried out to evaluate several commonly used procedures for obtaining bound shifts. The results indicate that only two of these methods afford values which are reliably related to the actual bound shifts. In addition, both methods afford values for the association constant. Guidelines are suggested which allow a chemist to anticipate when each methods can be successfully employed.