In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Farrar will continue to study the solvation of selected cations by photodissociation in mass-selected solvated cluster ions. Alkaline earth and early transition-metal cations will be solvated with variable numbers of polar solvents such as NH3 or H2O. The solvation process will be assessed by determining energies of low-lying electronic states and by vibronic analysis of isotopic clusters of solvent. Two-color and photochemical hole-burning experiments are proposed to examine thornier issues dealing with these broad cluster spectra. Ab initio calculations will allow comparison of vibrational frequencies in excited electronic states. The goal of this research is to understand the steps involved when isolated atomic ions in the gas phase acquire shells of solvent molecules, such as water, ammonia, or alcohol, in liquid or solid phases. Such information is important, because different solvents have varying affinities for a given ion, and these solvent shells can alter the chemical and physical properties of the ion substantially. These studies have application in understanding ion-molecules reactions which happen in the upper atmosphere, for example, or during plasma deposition processes
