On the triplet lifetime in free, photo-excited C60

It has recently been suggested that the lifetime of the lowest triplet state in multiphoton-excited C60 is much longer than anticipated. If true, this would invalidate the assumption of internal thermal equilibrium in the description of statistical decay processes of the molecule, such as thermionic emission. We present pump–probe measurements which show that the lifetime is below 1 μs at vibrational excitation energies of 6.5 eV, and that it decreases further to 40 ns at 10 eV.