Next Generation Experiment and Theory for Photoelectron Spectroscopy

Our understanding of the structure of molecules and the nature of the chemical bond has developed in tandem with our ability to measure the characteristics of the outer (valence) electrons that control chemical bonding. A key tool in this development has been photoelectron spectroscopy, whereby a high-energy burst of light removes an electron from the molecule. By measuring the energy of the outgoing electron and the direction in which it travels, we can obtain detailed information on the arrangement of the electrons and the nuclei in the molecule.

Chemistry is very dynamic, with atoms and molecules in constant motion and chemical reactions defined by associated changes in structure and bonding. Measuring chemical dynamics in real time, from reactants to products, is challenging and requires probes capable of resolving the changes in the arrangement of the valence electrons responsible for chemical bonding. Using ultrashort pulses of light, we can make photoelectron spectroscopy measurements with sufficient time-resolution to track the dynamic changes in the molecular electronic structure during reactions.

We will use new light sources and advanced theory to provide detailed measurements and analysis of light-induced chemical dynamics. The experiments will take advantage of high harmonic generation based light sources and high intensity lasers to monitor all of the structures important during photochemical reactions. The theory developments will combine state-of-the-art simulations of quantum molecular dynamics with new methods to calculate photoelectron spectra with high accuracy, allowing accurate images to be extracted from the experimental data to achieve a detailed mapping of the chemical reactions. This research will enable better understanding of the driving forces that control the outcomes of photochemical reactions and allow new methods to control, design, and direct chemical reactivity.