Photoelectron spectroscopy of mass-selected cluster anions

Photoelectron spectra of copper cluster anions have been obtained in two laboratories (Colorado and Rice Universities), yielding measurements for vertical electron binding energies and adiabatic electron affinities as a function of cluster size. The overall trend observed is well described by a classical spherical drop electrostatic model. Excited electronic states in the photoelectron spectra show distinct evidence for the buildup of band structure of the metal. Further studies are reported on other metals in which the d electrons play a more important role in the electronic structure. Preliminary work is reported on photoelectron spectra of negative ions of semiconductor materials