19F NMR and EPR study of fluorinated buckminsterfullerene C60F58 Original Research Article

Solid state 19F NMR in the temperature range from 96 to 366 K and room temperature EPR studies of fluorinated buckminsterfullerene C60F58 have been carried out. The temperature dependence of the line width and the spin–lattice relaxation time show hindered molecular motion with the activation energy of ΔEa=1.9 kcal/mol. Neither phase transition nor random rotation of C60F58 have been obtained. The spin–lattice relaxation rate is strongly affected by the presence of paramagnetic centers, namely, dangling C–C bonds yielding localized unpaired electrons. Such broken bonds are caused by C–C bond rupture in a cage-opened structure of hyperfluorinated species.