The possible role of coherent vibrational motion in ultrafast photo-induced electron transfer remains unclear despite considerable experimental and theoretical advances. We revisited this problem by tracking the back-electron transfer (bET) process in Betaine-30 with broadband pump-probe spectroscopy. Dephasing time constant of certain high-frequency vibrations as a function of solvent shows a trend similar to the ET rates. In the purview of Bixon-Jortner model, high-frequency quantum vibrations bridge the reactant-product energy gap by providing activationless vibronic channels. Such interaction reduces the effective coupling significantly and thereby the coherence effects are eliminated due to energy gap fluctuations, making the back-electron transfer incoherent.
|Number of pages||7|
|Journal||Chemical Physics Letters|
|State||Published - 2017|
Bibliographical notePublisher Copyright:
© 2017 Elsevier B.V.
- Bixon-Jortner model
- Coherent dynamics
- Electron transfer
- High frequency quantum vibrations
- Incoherent transfer
- Marcus inverted region
ASJC Scopus subject areas
- Physics and Astronomy (all)
- Physical and Theoretical Chemistry