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Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
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Strong Electronic Coupling-Induced Ultrafast Charge Transfer in Donor-Pyrene-Acceptor Systems.
Jumi Park1, Jooyoung Sung1,2, Dongho Kim1
1Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
The Journal of Physical Chemistry Letters
|February 26, 2021
Summary
Researchers studied charge transfer (CT) in donor-pyrene-acceptor (DPA) molecules. They observed ultrafast CT dynamics of ~200 fs, revealing insights into DPA systems compared to donor-pyrene-donor.
Area of Science:
- Photochemistry
- Molecular Spectroscopy
- Physical Chemistry
Background:
- Ultrafast charge transfer (CT) dynamics in donor-pyrene-acceptor (DPA) molecules are difficult to study due to overlapping locally excited (LE) and CT emission spectra.
- Understanding these dynamics is crucial for designing advanced molecular materials.
Purpose of the Study:
- To elucidate the ultrafast charge transfer (CT) processes in donor-pyrene-acceptor (DPA) molecules.
- To determine the mechanism and characteristics of CT in DPA systems.
Main Methods:
- Utilized various time-resolved spectroscopic measurements.
- Analyzed time-resolved fluorescence anisotropy decay profiles to determine CT rates.
Main Results:
- Successfully observed and quantified the ultrafast CT rate of approximately 200 femtoseconds (fs) in DPA molecules.
- Identified isoenergetic potential surfaces for LE and CT states in DPA systems.
- Demonstrated strong electronic coupling between LE and CT states upon acceptor introduction.
Conclusions:
- The observed solvent-independent ultrafast CT occurs via an adiabatic potential energy surface.
- Charge transfer characteristics are significantly enhanced in DPA molecules compared to donor-pyrene-donor systems.
- The findings provide a deeper understanding of CT mechanisms in DPA molecules.
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