Difluoromethyl group chemical shifts

When a CF2H group is attached to an ammonium nitrogen, its fluorines are considerably shielded relative to the respective amine. Thus, the fluorine chemical shifts of difluoromethyl trialkyl ammonium salts are in the -113- to -115-ppm range, as exemplified by difluoromethyl triethyl ammonium chloride (Scheme 4.27). 

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