Related Experiment Video
Updated: Sep 17, 2025

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
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.
Abstract:
Molecular structure, solvent/matrix, the surrounding environment, and molecular vibrations can influence the excited-state proton transfer (ESPT) process. Theoretical studies predict that light-matter strong coupling can modify the energy barrier for proton transfer reactions. Here, we experimentally explore the role of vibrational strong coupling (VSC) on the ESPT using the weak photoacid, 7-hydroxy-1-naphthalenesulfonate (N8S) as the probe. The ESPT in N8S can occur through a solvent/matrix bridge connecting the proton-donating and accepting units. To check the role of VSC, we embedded N8S in a poly(vinyl alcohol) (PVA) matrix and strongly coupled the ─OH stretching vibrational modes of PVA. The steady-state and time-resolved emission analysis reveal that the quantum yield of RO- emission and the ESPT rate constant enhance by a factor of two under VSC, compared to the noncavity, half-cavity, and off-resonance films. Our findings indicate that VSC can be a tool to control the proton transfer processes, opening avenues for developing physically tunable photoacid-based sensors.
Related Concept Videos
Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
NMR Spectroscopy: Spin–Spin Coupling
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
Spin–Spin Coupling: One-Bond Coupling

