| Little imagination is needed to appreciate the importance of water, H2O, and the hydroxyl radical, OH, in our world. Water is a very stable end product, and OH will extract a hydrogen atom from almost any other molecule to become water. For this reason, OH is known as the detergent of our atmosphere. While there is a tremendous body of information and knowledge on the static and dynamics properties of water (and much less for OH), on the microscopic scale - the basis for all further understanding - much is unknown. In this proposal we request CW-ECHO funding to continue an ongoing research project on energy transfer processes in the water molecule and expand the project to include the OH radical and its chemical reactions. The present project will come to a close in early 2009, just at the moment where the most exciting results are being obtained. Our present experiments probe the intermolecular potentials of water with collision partners H2, D2, He, Ne, Ar, and Xe using state-to-state crossed-beam inelastic scattering combined with velocity map imaging. We can now obtain the data and analyze it properly. We still need to use this data, in collaboration with leading theorists, to test and improve the quality of intermolecular potentials for these systems. The best test of theory, the first step in the proposed research, will be to obtain new data on inelastic scattering of the D2O and HOD isotopomers, and to isolate the scattering partner para-H2 and ortho-D2. The following step is to convert H2O to OH using our highly efficient discharge source and study first the inelastic scattering of OH with the above collision partners. The final, key, part of the project will be to collide OH with H-atom containing partners such as CH4 and H2, and to image one or both of the reaction products. By adding full state selection and orientation of the OH reactant, a field of research that our department in Nijmegen in famous for, this work will generate a new, unique, and complete data set for understanding, in full detail, the microscopic dynamics of water and hydroxyl radicals. |
