Time-resolved photodissociation and threshold collision-induced dissociation of anionic gold clusters

Bond dissociation energies and fragmentation patterns of small gold anionic clusters, Au-n(-), are studied by the time-resolved photodissociation lifetime (n = 6, 7) and energy-resolved threshold collision-induced dissociation (n = 2-7) methods. The main fragmentation channels are found to be loss of an atom or loss of a dimer. Time-resolved photofragmentation and both prompt and delayed electron loss are observed upon photon absorption. Dissociation energies are extracted using a statistical model for the unimolecular decomposition following collisional excitation or photoexcitation. Values obtained from the two methods overlap within the error bars. Dissociation energies for the loss of an atom from gold cluster anions, D-0(Au-n-1(-)-Au), show even-odd alternation. (C) 2000 Elsevier Science B.V. All rights reserved.