University of Illinois Urbana-Champaign

Ultrafast Dynamics Of Two- And Three-body Dissociation Captured By Core-to-valence Transient Absorption Spectroscopy

Tross, Jan

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TA05_1.pptx
6075.pdf

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https://hdl.handle.net/2142/116574

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Title
Ultrafast Dynamics Of Two- And Three-body Dissociation Captured By Core-to-valence Transient Absorption Spectroscopy
Author(s)
Tross, Jan
Contributor(s)
  • Ramasesha, Krupa
  • McCaslin, Laura M.
  • Schrader, Paul
  • Cole-Filipiak, Neil C.
Issue Date
2022-06-21
Keyword(s)
Mini-symposium: Spectroscopy meets Chemical Dynamics
Abstract
Molecular photodissociation is central to numerous photochemical processes relevant to atmospheric chemistry and photocatalysis. As platforms to understand the ultrafast excited state dynamics underlying complex molecular photodissociation mechanisms, we studied the ultraviolet photodissociation of two gas-phase molecules: acetyl iodide\footnote{P. M. Kroger and S. J. Riley J. Chem. Phys. 67, 4483 (1977); https://doi.org/10.1063/1.434589}, which is a photolytic precursor for the acetyl radical, and iron pentacarbonyl\footnote{M. Poliakoff and E. Weitz, Acc.Chem.Res. 1987, 20, 11, 408-414; https://doi.org/10.1021/ar00143a004}, which is a model photocatalyst system. Using ultrafast extreme ultraviolet transient absorption spectroscopy, we followed the photodissociation dynamics of these molecules via core-to-valence transitions of their respective heavy atom constituents (I and Fe), giving access to atom-specific signatures of excited electronic states.\\ In acetyl iodide, we observe transient features with sub-100 fs lifetimes associated with the excited state wavepacket evolution prior to dissociation. These features then evolve to yield spectral signatures corresponding to the dissociation of the C-I bond. In iron pentacarbonyl, we observe transient features evolving on 100 fs to few-picosecond timescales due to excited state loss of carbonyl groups. We combine experimental findings with quantum chemical calculations to gain insight into the photodissociation dynamics.\newline SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.\\ SAND No. SAND2022-2283 A
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
text
Genre of Resource
Conference Paper / Presentation
Language
eng
Handle URL
https://hdl.handle.net/2142/116574
DOI
https://doi.org/10.15278/isms.2022.TA05
Copyright and License Information
Copyright 2022 held by the authors

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Abstracts & Presentations - 2022 International Symposium on Molecular Spectroscopy PRIMARY