Nuclear magnetic resonance shift reagents: Abnormal 13C shifts produced by complexation of lanthanide chelates with saturated amines and n-butyl isocyanide

摘要

Lanthanide-induced shifts of 13C nuclear magnetic resonances are reported for several amines and n-butyl isocyanide. Contact contributions to such shifts, especially of ß carbons, are clearly important for the chelates of Eu+3 and Pr+3. The importance of contact terms is shown to change in a rather predictable manner with the structure of the amine.