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Updated: Mar 14, 2026
05:33
Light-Induced In Situ Transmission Electron Microscopy for Observation of the Liquid-Soft Matter Interaction
Published on: July 26, 2022
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Direct observation of light-driven, concerted electron-proton transfer.
Christopher J Gagliardi1, Li Wang2, Prateek Dongare1
1Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290.
Summary
Phenols and N-methyl-4,4′-bipyridinium cation form hydrogen-bonded adducts. These adducts undergo optically induced, concerted electron-proton transfer (photoEPT), confirmed by ultrafast spectroscopy.
Area of Science:
- Photochemistry
- Supramolecular Chemistry
- Physical Chemistry
Background:
- Hydrogen-bonded adducts between phenols and N-methyl-4,4′-bipyridinium cation (MQ+) are formed in aqueous solution.
- These interactions are studied in the context of electron-proton transfer mechanisms.
Purpose of the Study:
- To investigate the formation of hydrogen-bonded adducts between specific phenols and MQ+.
- To elucidate the mechanism of optically induced, concerted electron-proton transfer (photoEPT) in these systems.
Main Methods:
- UV-visible spectroscopy to detect spectral features of adducts.
- Ultrafast transient absorption spectroscopy to probe reaction dynamics.
Main Results:
- Low-energy, low-absorptivity features in UV-visible spectra indicate adduct formation.
- Ultrafast measurements show instantaneous spectral changes consistent with concerted electron-proton transfer (EPT).
- Vibrational coherence and relaxation were observed on the picosecond timescale.
Conclusions:
- Phenols form hydrogen-bonded adducts with MQ+ in aqueous solution.
- Optically induced, concerted electron-proton transfer (photoEPT) is confirmed as the mechanism.
- Ultrafast dynamics reveal vibrational coherence and relaxation pathways in the photoEPT process.
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