Tendencies in Chemical Shifts in the 19F NMR Spectra of Fluorine-containing Compounds

Anomalous tendencies in the ¹⁹F NMR chemical shifts of certain fluorine-containing, primarilyorganofluorine, compounds are explained. The explanation is based on the positive charge concept, accord-ing to which in the a series of Y-Z-M molecules containing a positively charged atom Z (the Y, M atomsare more electronegative than Z) the ionicity of the Z-Y bond increases with increasing electronegativity ofthe M atom (atomic group).