Ultrafast hot-electron dynamics observed in Pt( -)(3) using time-resolved photoelectron spectroscopy

Time-resolved two-photon photoelectron spectra have been measured for free Pt( -)(3) using femtosecond pulses of 1.5 eV photon energy in a pump-probe configuration. The time-dependent photoelectron distribution reveals a lifetime of optically excited states of less than 70 fs. Such an unexpected fast electron relaxation in Pt( -)(3) suggests the existence of inelastic electron-electron scattering processes in a triatomic cluster which result in a lifetime similar to those of bulk metals.