FWF - Chemical Dynamics - Ultrafast Chemical Dynamics

Project: Research project

Description

The formation and breaking of chemical bonds are the most fundamental steps in chemical reactions.
Studying the quantum dynamics that underlie these processes in real time is thus of great interest for
physics, chemistry and many other fields of research.
The aim of the proposed experiments is to gain a deeper understanding of dynamic processes in
molecules from a novel perspective. The project will push the method of tabletop femtosecond
transient absorption spectroscopy into new territories, utilizing probe pulses in the soft Xray regime
with photon energies beyond 100 eV. Femtosecond Xray pulses will be generated by highharmonic
generation. The novel method combines the advantages of Xray absorption spectroscopy and
femtosecond pumpprobe spectroscopy. Transitions involving corelevel electrons enable the study of
electronic and nuclear dynamics with elementspecificity and sensitivity to local valence electronic
structures. In the proposed experiments highorder harmonic probe pulses with photon energies up to
180 eV will provide access to the sulfur 2p edge, facilitating the study of the chemistry of sulfurcontaining
compounds. The temporal evolution of the molecular valence electronic structures will be
monitored in realtime and from the perspective of distinct reporter atoms. Experiments in Berkeley and
Graz will probe spinorbit and vibrational wave packets in neutral and strongfield ionized carbon
disulfide as well as the photoinduced breaking of the SC bond in cyclic thiophene molecules (ringopening
reaction), which is of particular relevance for energy related technologies. Especially, the
introduction of wellcontrolled ultraviolet (UV) excitations is an important next step in the field of
femtosecond Xray transient absorption spectroscopy, which will facilitate the investigation of many
naturally occurring photochemical processes triggered by UV sunlight under controlled conditions.
Exploring the most fundamental mechanisms in nature is the basis for understanding complex systems
and their timedependent behavior. The development of novel methods for the study of ultrafast photoinitiated
molecular dynamics will create new opportunities to unravel key processes in physics,
chemistry, life sciences, material science as well as environment and energy related technologies.
StatusFinished
Effective start/end date20/10/1419/06/17