Doubly charged negative ions of carbon-60

We report the observation of long-lived (>10-3 sec) doubly charged negative ions of C60 in the gas phase. C60- and C602- ions are produced by laser desorption from a surface covered with C60 molecules and are believed to be produced by negative surface ionization from the laser-heated surface. Pseudopotential calculations indicate that C602- is slightly bound (electron affinity of C60-0.1-0.4 eV) relative to C60-.