F-19 NMR-STUDY OF 1-HALO-F-ADAMANTANES

An 'anomalous' variation of beta-fluorine chemical shifts with respect to the inductive effect in the F-19 NMR of a series of 1-halo-F-adama ntanes is reported. These fluorine chemical shifts are similar to the hydrogen chemical shift anomaly found in the corresponding hydrocarbon halides. Whereas the gamma-hydrogen chemical shifts can be rationaliz ed by the inductive effect, the gamma-fluorine chemical shifts have th e same 'anomalous' variation as found in the beta-fluorine chemical sh ifts.