Supplement for Ultrafast Dynamics of Energetic Additives in O2 Clusters

摘要

Extensive theoretical and experimental studies of the photochemistry of energetic cluster ions and the dynamics of molecular reactions within size- selected clusters have been carried out over the past three years. Photodetachment, photoelectron spectroscopy and photodissociation spectroscopy have been utilized to determine the structure of transient species: Incoherent control of reaction products in a cluster ion containing 35 atoms has been demonstrated and, more importantly, it has been shown that such a large tightly coupled complex can maintain a very non-statistical, chemically significant amount of excitation for at least 10 Ps. This result sets the time scale for possible control strategies. A new method has been developed to follow reaction dynamics in real time, starting with negative ion photodetachment to produce in energetic neutral, followed by a multiphoton ionization with a delayed ultrafast probe pulse. Direct information about coherent motion of the solvent itself is obtained by following the absorption recovery as detected by specific two-photon products, since it is the instantaneous cage configurations that determine the product branching ratios at given pump-probe delays.