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Updated: Nov 22, 2025
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Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
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Photodissociation of aqueous observed with liquid-phase ultrafast mega-electron-volt electron diffraction.
K Ledbetter, E Biasin1, J P F Nunes2
1Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Structural Dynamics (Melville, N.Y.)
|January 8, 2021
Summary
Researchers developed liquid-phase ultrafast electron diffraction (LUED) to observe chemical reactions in solution. This new method captured the bond expansion and recombination dynamics of tri-iodide dissociation in real-time.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Materials Science
Background:
- Understanding ultrafast chemical reactions in solution is crucial for various scientific fields.
- Direct observation of structural dynamics at femtosecond resolution is challenging.
- Existing methods often lack the speed or resolution to capture key reaction intermediates.
Purpose of the Study:
- To develop and demonstrate a novel method for observing ultrafast structural dynamics in liquid-phase chemical reactions.
- To enable direct visualization of photochemical reaction mechanisms in solution with unprecedented time resolution.
- To investigate the photodissociation of tri-iodide as a model system.
Main Methods:
- Utilized mega-electron-volt ultrafast electron sources for high temporal resolution.
- Employed vacuum-compatible sub-micron thick liquid sheet jets for stable liquid samples.
- Combined these technologies to perform liquid-phase ultrafast electron diffraction (LUED).
- Initiated photodissociation using a 400 nm laser pulse.
Main Results:
- Successfully demonstrated the viability of liquid-phase ultrafast electron diffraction (LUED).
- Measured the average speed of bond expansion during tri-iodide photodissociation within the first 750 fs.
- Directly captured geminate recombination dynamics on the picosecond timescale.
Conclusions:
- LUED is a powerful technique for studying ultrafast dynamics in solution.
- The method provides direct insights into bond breaking and reformation processes.
- This advancement opens new avenues for investigating complex photochemical mechanisms.
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