In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Dudley Herschbach of Harvard University will continue his studies using molecular beam techniques to examine the effect on reactive collisional and spectroscopic processes of the alignment of molecules in static electric or magnetic fields. The current project proposes to develop a more general method of spatially trapping molecules than investigated previously which uses an intense laser field to confine suitable molecules for times on the order of hours. In addition to constructing the trapping apparatus, the PI will use directional molecules to study phenomena such as rotationally inelastic collisions of oriented molecules, vector correlations in atom-diatom reactions, and the shift of chemical equilibrium induced by molecular alignment in a strong magnetic field. Normally, when molecules react chemically, the mutual orientation of the colliding partners is completely random. Prof. Herschbach is developing a general method for orienting the molecules prior to reaction in order to see if there is an effect on the outcome. Using this technique, chemical reaction mechanisms can be elucidated at an unprecedented level of detail. The use of oriented molecular targets in molecular beam studies of chemical reactions will lead to much more accurate and detailed pictures of gas phase reaction mechanisms.
