PHOTODETACHMENT OF SMALL WATER CLUSTER ANIONS IN THE NEAR-INFRARED THROUGH THE VISIBLE REGION

Water cluster anions were efficiently generated by attachment of slow photoelectrons ejected from laser-excited zirconium metal surface, and photodetachment cross sections for (H2O)(n)(-) (n = 2, 6, 7, and 11) were measured for a photon energy range of 0.74-2.54 eV. A gradual dec rease of the cross section with the photon energy was observed for all the species. It was also found that the larger cluster exhibits the l arger cross section. Size-dependent features of the spectra, were disc ussed in relation to the excess electron localization with evolution o f the cluster size.