Fullerene triplet state production and decay: R2PI probes of C60 and C70 in a supersonic beam

Abstract Lifetimes of the lowest triplet state of the two most stable fullerenes, C 60 and C 70 , were measured in a supersonic beam by two-color resonant two-photon ionization. When prepared by intersystem crossing from the singlet manifold, excited at 4.03 eV, these triplet states were found to have lifetimes of 42 and 41 μs, respectively. The energies of these triplet states (1.7 and 1.6 eV, respectively) were measured by photoelectron spectroscopy of the corresponding negative ions.