Femtosecond photoelectron spectroscopy of the photodissociation of Au3-

The photodissociation of Au-3(-) is studied by time-resolved photoelectron spectroscopy using femtosecond laser pulses. The spectra show the time evolution of the electronic structure after photoabsorption. Absorption of a "pump" photon results in the formation of a metastable activated complex (Au-3(-))*, which decays by dissociation into Au-1(-) + Au-2 and, less favorably, into Au-2(-) + Au-1. Photoelectron spectra recorded with the "probe" laser pulse at increasing delay time first show the spectrum of the intact Au-3(-), then that of the activated complex (Au-3(-))* and, finally, the spectra of the two charged dissociation products Au-1(-) and Au-2(-). The lifetime of (Au-3(-))* decreases dramatically with increasing energy of the "pump" photon. (C) 1998 Elsevier Science B.V.