The stability of singly and multiply charged La@C80 and La@C82 ions determined from kinetic energy release measurements

We have measured the kinetic energy release distributions for unimolecular C2 loss from singly and multiply charged endohedral La@C80z+ and La@C80z+ ions for charge states z = 1–3. Using finite heat bath theory, we deduce the dissociation energies for loss of C2. The charge state z has no statistically significant effect on the dissociation energies. The dissociation energies of endohedral fullerene ions are larger than those of the corresponding empty fullerene ions by a few tenths of an electron volt, but the differences are barely statistically significant. The small differences also imply that the complexation energies of La@Cnz+ and La@Cn − 2z+ are identical within the experimental errors, for n = 80 and 82 and all charge states.