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Transient chiral dynamics revealed by two-dimensional circular dichroism spectroscopy
Zihui Liu1, Ajay Jha2,3,4, Xian-Ting Liang1
1Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P.R. China.
Physical Review. E
|June 17, 2023
Summary
Chirality influences photochemical processes. Two-dimensional circular dichroism (2DCD) spectroscopy reveals how chiral interactions drive energy transfer in coupled molecular systems, like the Fenna-Matthews-Olson complex.
Area of Science:
- Photochemistry
- Molecular Biophysics
- Spectroscopy
Background:
- Chirality is fundamental to life's evolution.
- Understanding chiral influences on molecular processes is crucial.
- Excitonically coupled dimeric systems serve as models for energy transfer studies.
Purpose of the Study:
- Investigate the role of chirality in photoinduced energy transfer.
- Utilize 2DCD spectroscopy to probe transient chiral dynamics.
- Examine chiral contributions to energy transfer pathways in coupled systems.
Main Methods:
- Employed circularly polarized laser pulses in 2D electronic spectroscopy.
- Constructed 2DCD spectral maps to observe chiral dynamics.
- Analyzed time-resolved peak magnitudes and cross-peak kinetics.
Main Results:
- Identified chirality-induced population dynamics via 2DCD peak magnitudes.
- Observed weak initial chiral interactions, followed by downhill energy transfer.
- Demonstrated the impact of excitonic coupling on energy transfer pathways.
Conclusions:
- 2DCD spectroscopy effectively resolves chiral interactions and population transfers.
- Chirality plays a significant role in energy transfer mechanisms.
- Findings are applicable to biological systems like the FMO complex.
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