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

Tross, Jan

Permalink

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

Description

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

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

Owning Collections