NMR study of acceptor doped fullerenes (MF6)2C60 (M=As, Sb)

We report on 13C and 19F nuclear magnetic resonance study of acceptor doped fullerenes showing p-type semiconductor behavior. Room temperature 19F spectra are characteristic for rotating (MF6−) complexes, while the 13C spectra show that fullerene molecules are not mobile at temperatures up to 365 K. Reduction of the 13C chemical shielding anisotropy of (MF6)2C60 in comparison to solid C60 is assigned to the charge transfer between C60 and intercalated species.