Ultrafast Chemical Dynamics on Complex, Excited State Energy Landscapes
Abstract
Major Goals: The project explores the structures and the time-resolved chemical dynamics of important molecular systems in excited states. Two complementary techniques are developed and applied to representative model systems that illustrate a wide range of ultrafast chemical dynamics processes. Understanding the structures and chemical dynamics of molecules in their excited states is of great importance for basic science and myriad applications within and outside of Chemistry. The project develops two experimental tools and applies them to important molecular systems. Because the experimental methods are complementary, their simultaneous application to the same systems provides deeper insights into the molecular dynamics than each technique would give in isolation. The experimental methods are ultrafast time resolved gas x-ray diffraction, which is performed at SLACs LCLS light source, and time-resolved Rydberg fingerprint spectroscopy. All these methods measure the structures of molecules in excited states, with a time resolution of <100 fs for both the x-ray diffraction and the Rydberg spectroscopy. The Rydberg Fingerprint Spectroscopy method has been developed with ARO funding in a prior period. The molecular systems to be studied include: the ring-opening reaction of 1,3-cyclohexadiene, where we seek to observe, over a broad range of excitation energies, the structure of the molecule as it passes the conical intersections; the conformeric structure and dynamics of N-methyl morpholine, which features fascinating conformeric relaxation dynamics; and the effect of solvation on the charge delocalization of tertiary amines. By focusing on structurally well-defined molecules and molecular clusters, the project advances our knowledge of molecules in excited electronic states, their chemical dynamics, and the effect of solvent environments. This aids numerous applications and is also valuable to the continued development of computational methods.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 28, 2021
- Accession Number
- AD1186603
Entities
People
- Peter M. Weber
Organizations
- Brown University