Lanthanide Shift Reagents XIV Equilibrium Binding Constants for Europium Shift Reagent with Alkyl and Aryl Esters

Methods have been developed for measuring the equilibrium binding constants (K) for lanthanide shift reagents with donor substrates. Although Infrared Spectroscopy proved useful¹ for determining the binding of substituted anilines to the tris-tetramethylheptanedionate of Ytterbium, it was found that NMR was more sensitive and applicable to a wider range of substrates than simple alcohols and amines^2,3. The NMR procedure of progressive