Abstract
In recent years lanthanide shift reagents have become increasingly valuable as aids in the analysis of organic structures by nmr spectroscopy.2. They can be used qualitatively in order to simplify nmr spectra, and the lanthanide induced shifts can also be used quantitatively for the mathamatical analysis of a proposed structure.3–6 Whatever the particular case may demand, these reagents can be utilized most effectively when the equilibria between shift reagent and substrate are well understood. We have previously reported7 the binding abilities of a variety of functional groups with Eu(fod)3, and we have also discussed8 the effects of structural variation on the corresponding equilibria of ketones. We now consider structural effects on the association equilibria for a variety of nitriles with Eu(fod)3 in CCl4.