A Comparison of Strong and Weak Field Ionization as a Probe of Excited State Molecular Dynamics

Yusong liu; Spencer Horton; Pratip Chakraborty; Spiridoula Matsika; Philipp Marquetand; Tamas Rozgonyi; Varun Makhija; R. Forbes; Paul Hockett; Rune Lausten; Albert Stolow; Thomas Weinacht

A Comparison of Strong and Weak Field Ionization as a Probe of Excited State Molecular Dynamics

ORAL

Abstract

Ionization can serve as a universal probe of excited state molecular dynamics, such as internal conversion, dissociation, and isomerization. We conduct time-resolved photoelectron and photoion spectroscopy measurements of excited state state dynamics in both weak field (UV-pump/VUV-probe) and strong field (UV-pump/IR-probe) ionization (WFI and SFI). We investigate the relative merits of WFI versus SFI as probes in two different classes of molecules - halogenated methanes (CH2I2) and cyclic organic molecules (uracil). Experimentally, both WFI and SFI approaches show similar dynamics - CH2I2 undergoes rapid internal conversion followed by dissociation and uracil has substantial population trapping in the excited state in addition to rapid internal conversion back to the ground state. Theoretically, we compare the experimental results with electronic structure and dynamics calculations. We find that while SFI and WFI provide qualitatively similar information about the excited state dynamics, only WFI results can be compared quantitatively with calculations.

May 30, 2018, 11:06 AM – May 30, 2018, 11:18 AM

Authors

Yusong liu

State Univ of NY- Stony Brook,US
Spencer Horton

State Univ of NY- Stony Brook,US
Pratip Chakraborty

Temple University, US
Spiridoula Matsika

Temple University, US
Philipp Marquetand

University of Vienna, Austria
Tamas Rozgonyi

Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences
Varun Makhija

University of Ottawa, Canada, University of Ottawa, Department of Physics
R. Forbes

Department of Physics, University of Ottawa, Ottawa, Canada, University College London, UK, University of Ottawa, Canada, University College London, University of Ottawa
Paul Hockett

National Research Council, Canada, National Research Council of Canada
Rune Lausten

National Research Council, Canada
Albert Stolow

University of Ottawa, National Research Council, Canada, University of Ottawa, Departments of Physics and Chemistry
Thomas Weinacht

State Univ of NY- Stony Brook,US, Stony Brook University