LASER IONIZATION SPECTROSCOPY OF AG(NH3)(N) CLUSTERS

The ionization and the fragmentation properties of Ag(NH3)(n) heteroclusters have been studied. The measured ion yield spectra near the threshold for complexes with n = 2-20 indicate strong differences of the cluster geometry in the electronic ground and in the ionized state, respectively. For smaller clusters (n less than or equal to 6) in the neutral ground state the nonsolvated Ag atom is localized near the surface of the complex. A modification of the surface structure at the transition to larger clusters (n greater than or equal to 7) is suggested by significant changes in the ionization and fragmentation behaviour. Preliminary results of ab initio calculations confirm the conclusion that due to the correlation interaction between the valence electron and the 4d electrons of the AE atom no solvation effects occur.