OBSERVATION OF ATOM-LIKE NITROGEN IN NITROGEN-IMPLANTED SOLID C-60

A new paramagnetic defect in solid C-60 was produced by nitrogen impla ntation in solid C-60 The hyperfine splitting and the isotope effect u nambiguously show that the paramagnetic center contains one nitrogen n ucleus. The hyperfine interaction is isotropic, its value is comparabl e to that of the free nitrogen atom, and the spin of the electron syst em is S = 3/2, as in atomic nitrogen. The complex responsible for this center is soluble in toluene and CS2 and is stable. We suggest that t he complex consists of nitrogen inside C-60.