| Abstract: | The NMR spectra of acetone, adamantanone and 1-adamantanecarbonitrile have been studied in the presence of Eu(fod)3 in various solvents. A substantial solvent dependence is found for the association constants between shift reagent and substrate. The magnitude of the association constants is correlated with solvent polarity, and a tenfold decrease in K1 is observed upon changing from carbon tetrachloride to the more polar dichloromethane. Only a very small solvent dependence is observed for the bound shifts. The relative bound shifts (and therefore the structures of the LS complexes) are found to be solvent independent. The small solvent dependence of the absolute magnitude of the bound shifts for the LS complexes is suggested to result from experimental errors. |
