THE SOLVATION OF IODINE ANIONS IN WATER CLUSTERS - PES STUDIES

We have measured the photoelectron-spectra of I- (H2O)n clusters in the size range n=1-60. We have found that the first six water molecules form a solvation layer with an average 0.35 eV electrostatic stabilization of the anion. At larger cluster sizes the electrostatic stabilization of water does not fit a continuous dielectric solvent. The most stable structures of the clusters consist of internally solvated anions. In the size range n=34-40 we have found evidence for existence of cluster structures with surface solvated anions.