Gas-Phase Molecular Dynamics 

  In this program, we investigate the energetics, dynamics, and kinetics of chemical reactions resulting from molecular collisions in the gas phase. Details of the structure and behavior of short-lived intermediates involved in reactions important in combustion chemistry are studied using both experimental and theoretical probes. The goal of this work is a fundamental understanding of the chemical reactivity and energy flow in the transient molecular species involved in combustion processes. This program is part of a larger grouping, the Center for Spectroscopy in Molecular Science, within the BNL Chemistry Department with participation from local university investigators.

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Photoinduced Molecular Dynamics in the Gas and Condensed Phases

  The goal of this program is to elucidate the dynamics of photoinduced fragmentation processes of molecules in the gas-phase and on surfaces through the use of state- and energy-resolved spectroscopies. Particular emphasis is placed on systems or processes that provide information on the spectroscopy and dynamics of chemical intermediates which are important in combustion and surface catalytic reactions. Coherent VUV and ultra-fast laser sources are used to induce photoionization, photodissociation, surface desorption and intramolecular motion, the dynamics of which are probed by state- and/or energy-resolved photoelectron and photoion methods. Dissociation and ionization measurements at high laser intensities investigate the response of molecules to intense fields well beyond the perturbative regime which introduces new selectivity and "field-induced" fragmentation pathways. Further studies of the effects of well-characterized fields on simple, isolated systems are also under investigation with the ultimate goal of optimal control of physical and chemical processes. The excitation and energy transfer mechanisms responsible for photodesorption and photofragmentation of molecules adsorbed on metal surfaces are being explored as part of a new effort in surface photochemistry with applications to combustion and catalysis. Thermal and laser-induced surface oxidation and atom-atom recombination reactions are also being investigated in an effort to probe the transition state dynamics of surface reactions that lead to gas-phase products.