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Global Lifetime Analysis on Excited Three-State Reactions
Seung-Woo Lee1, Seong-Jun Kim1, Oh-Hoon Kwon1
1Department of Chemistry, College of Natural Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
The Journal of Physical Chemistry. A
|June 3, 2025
Summary
This study presents analytical solutions for analyzing complex excited-state chemical reactions. The method accurately determines reaction mechanisms and rates for processes like excited-state proton transfer.
Area of Science:
- Photochemistry and Photophysics
- Chemical Kinetics
- Spectroscopy
Background:
- Excited-state chemical kinetics is crucial for understanding ground-state reactions and advancing light-energy applications.
- Global lifetime analysis of time-resolved spectral data aids in identifying reaction intermediates and determining rate constants for complex, reversible reactions.
Purpose of the Study:
- To develop and validate analytical solutions for three-state reactions in the excited state, including those with partial or full reversibility.
- To apply this method to elucidate the full reaction mechanism, rate constants, kinetic order, spectral shapes, and initial species amounts.
Main Methods:
- Global lifetime analysis of time-resolved spectral data.
- Development of analytical solutions for three-state excited-state reactions.
- Application to time-resolved fluorescence spectra of photoacid proton transfer in binary solvent mixtures.
Main Results:
- Successfully elucidated all rate constants and kinetic orders for a reversible excited-state proton transfer reaction.
- Determined the emission spectral shape and initial amounts of each emitting species.
- Validated the analytical approach using a controlled experimental system.
Conclusions:
- The presented analytical protocol provides a systematic method for investigating complex excited three-state reactions.
- This approach is broadly applicable beyond the studied proton-transfer reaction, offering insights into various photochemical processes.
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