TRANSIENT SOLVENT DYNAMICS AND INCOHERENT CONTROL OF PHOTODISSOCIATION PATHWAYS IN I-2(-) CLUSTER IONS

Detailed time-resolved photodissociation and caging dynamics in cluste rs are studied using I-2(-)(OCS)(11) as a model system. We report new observations of product channel-dependent properties of nuclear cohere nce in the dissociated chromophore, reflecting complex dynamics of the solvent cage. The coherence feature is most pronounced in the caged t wo-photon channels and its relative amplitude increases with the produ ct size. Shorter delays, on the time scale of coherent I...I- motion, favor larger products, allowing for incoherent control of two-photon d issociation pathways by appropriately timing the two laser pulses. As an example of such control, I-2(-) (OCS)(2) is produced most effective ly by a limited set of pump-probe excitations at short delays. We emph asize generality of these results that relate to caging dynamics in an y cluster ions. (C) 1998 American Institute of Physics.