Abstract
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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 500-506 |
| Number of pages | 7 |
| Journal | Chemical Physics Letters |
| Volume | 683 |
| DOIs | |
| State | Published - 2017 |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy
- Physical and Theoretical Chemistry
Keywords
- Bixon-Jortner model
- Coherent dynamics
- Electron transfer
- High frequency quantum vibrations
- Incoherent transfer
- Marcus inverted region