Hyperfine Study of the 19F Isomer as a Substitute for Oxygen in MnO

The paramagnetic shift of the 19 F isomer ( I =5/2, T 1/2 =88 nsec) at the oxygen site in MnO at room temperature was measured to be 2.6±0.5% by the time differential purturbed angular distribution method. The probe of 19 F isomer, produced by 16 O(α, p) 19 F reaction, took the place of the oxygen. The shift is compared with those obtained by 17 O NMR in MnO and by 19 F NMR in few fluorides, and is attributed to the covalent nature of the usual-fluorine bond.