EVIDENCE FOR THE PRESENCE OF CONTACT TERM CONTRIBUTION TO LANTHANIDE-INDUCED ISOTROPIC SHIFTS IN 13C AND 19F NMR SPECTRA OF ALIPHATIC COMPOUNDS: CAUTION FOR APPLICATIONS OF LANTHANIDE SHIFT REAGENTS

Evidence for the presence of the contact term contribution besides the dipolar interaction has been presented in paramagnetic shifts induced by lanthanide shift reagents in 13C and 19F NMR spectra of several aliphatic alcohols, ketone, amines, and nitriles. Thus, it is suggested that caution should be exercised in their applications.

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