CHARGE-TRANSFER PHOTOCHEMISTRY IN ION MOLECULE CLUSTER COMPLEXES OF SILVER

Ion-molecule complexes containing silver atoms and silver clusters with 'adsorbed'' benzene, toluene, or acetone molecules are prepared in a supersonic molecular beam with pulsed-laser vaporization. Complexes are mass-selected in a reflection time-of-night spectrometer and excited with ultraviolet laser radiation in the 385-260-nm region. Atomic and diatomic metal complexes undergo ''dissociative intramolecular charge transfer'', yielding organic ions. Triatomic silver complexes undergo dissociation at the metal center without loss of the organic and/or undergo simple desorption of the neutral organic at different wavelengths. The mechanism and energetics of this new photochemistry are studied as a function of energy, number of metal atoms, and extent of complexation.