Time resolved millimeter wave absorption techniques were used in conjunction with a collisional cooling cell to study low temperature collisions between molecules and helium atoms. Measurement of low temperature inelastic cross sections is important both for understanding quantum collisions and for modelling the interactions of molecules in the interstellar medium. The 148 transitions were fit in a global analysis that uses a multistate Hamiltonian and takes into account the Fermi and Coriolis interactions between torsional states. Rotational constants were obtained for each torsional state by using a Watson A-reduced Hamiltonian. The addition of only three solvating water molecules to each reactant monomer ion results in at least an order of magnitude increase in the rate constant and a change in the reaction mechanism from electron transfer to proton transfer.
Work is currently underway to study individual reactions with the use of particle detector.
Aqueous cluster studies have lead to a reassessment of the electronic properties of bulk water, such as band gap, conduction band edge, and vacuum level. The results are presented in an energy diagram for bulk water which shows the utility of exploring the conduction band of water as a function of solvent polarization. The results are also compared to continuum expectations for small drops of water based on the bulk surface tension of water. Previous efforts to compute quantum reactive scattering matrix elements have been computationally intensive and expensive. Self-consistent Quasidegenerate Perturbation Theory M.R. Hoffmann, Yu.