Stability of Buckminsterfullerene, C60

We have measured delayed ionization of laser excited C60 molecules by detection of ions in coincidence with emitted electrons. This makes it possible to distinguish ionization of C60 from that of C58 molecules created by the dominant process, emission of C2. From the time dependence of the C60+ yield and the ratio of the yields of the two ions, we can determine both the dissociation energy, Ed=10.8±0.3 eV, and the pre-exponential factor, Ad∼3.4×1021 s−1 in the Arrhenius expression for the rate constant. The experiment has for the first time determined the power of photon emission from neutral C60, which is an important competing process. The radiation may be represented by emission of 1 eV photons, with a rate k∝T8 and with k=105 s−1 at T=4000 K.