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Updated: Sep 17, 2025
10:03
Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
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Exploring Excited State Proton Transfer in Thin Films Under Vibrational Strong Coupling
Malay Krishna Mahato1, Kavya S Mony1, Harsh Baliyan1
1Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bengaluru, 560012, India.
Angewandte Chemie (International Ed. in English)
|July 2, 2025
Summary
Vibrational strong coupling (VSC) enhances excited-state proton transfer (ESPT) in photoacids by a factor of two. This discovery offers new ways to control proton transfer reactions and develop tunable photoacid sensors.
Area of Science:
- Photochemistry
- Physical Chemistry
- Spectroscopy
Background:
- Excited-state proton transfer (ESPT) is influenced by molecular structure, environment, and vibrations.
- Theoretical studies suggest light-matter strong coupling can alter proton transfer energy barriers.
Purpose of the Study:
- To experimentally investigate the effect of vibrational strong coupling (VSC) on ESPT.
- To use 7-hydroxy-1-naphthalenesulfonate (N8S) as a probe for ESPT under VSC conditions.
Main Methods:
- Embedding N8S in a poly(vinyl alcohol) (PVA) matrix.
- Achieving VSC by strongly coupling PVA's ─OH stretching vibrational modes.
- Analyzing steady-state and time-resolved emission.
Main Results:
- VSC enhanced the quantum yield of RO⁻ emission by a factor of two.
- The ESPT rate constant also doubled under VSC conditions.
- Observed enhancements were compared to control films (noncavity, half-cavity, off-resonance).
Conclusions:
- Vibrational strong coupling can effectively control proton transfer processes.
- VSC presents a novel approach for developing physically tunable photoacid-based sensors.
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