C60 DOPED WITH ORGANIC CATIONS - MAGNETIC-RESONANCE MEASUREMENTS

''Doped'' C60 compounds were synthesized by the electrochemical reduct ion. We stabilize the reduced state of the fullerene using two organic cations of a different size: N-methyl-N-ethyl--morpholine+ and acridi zine+. The products of these two reactions precipitated as a powder on the platinum electrode and in the solution. The electrical conductivi ty of pressed pellets was below 10(-8) S/cm for both compounds. We emp loyed the Electron Paramagnetic Resonance and C-13 Nuclear Magnetic Re sonance measurements as the first characterization of these materials. The samples showed an EPR signal with the line width of 0.5 mT, which is due to the radical anion C60.-. We used broadband and Magic Angle Spinning techniques to obtain the C-13 NMR spectra. The main line in t he most of these spectra is the single line of the radical anion of th e C60 at about 142 ppm. This line appears approximately at the same po sition as in the pure C60 but it is broader. It suggests that the reor ientation of fullerene molecules is disturbed already at room temperat ure.