The research  in this project deals with the radical chemistry of mildly oxidizing environments such as found for atmospheric and combustion conditions.  Such studies will involve the radicals OH, CH₃,CH₃O, and NO₃ reacting with C₂H₄ and other small stable molecules. The most important goal of these studies is to generate a reaction path (or coordinate) and potential energy surface for the radical reactions of atmospheric and combustion related chemistry.  This goal will be achieved through a two pronged approach: experimental studies of the reactions at different vibronic or rovibronic levels of the reactant complex and possible product state identification if other radical or optically accessible species are generated; and an extensive theoretical effort to calculate the observed reaction surfaces, coordinates, and product state distributions. The four radicals of interest will be formed into ground state complexes with C₂H₄ or other small molecules in a supersonic expansion.
The ground state complex is not reactive because of a reaction barrier on this potential energy surface.  Reactions are initiated through photo excitation of the complexed radical.  The barriers to reaction on the excited state surfaces are typically small (ca. 1 kcal/mol) or non-existent. The advantage of this approach to the study of radical reactions is that the reaction is initiated at a known time (for dynamics studies), with a known total energy in the reactants, and with a known distribution of initial reactant states. The reactions within the complexes can be followed by optical/mass spectroscopy with nanosecond and picosecond or ¬ femtosecond time resolution to determine reaction dynamics and final product state distribution, and to identify the product species and channels.