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Updated: May 31, 2026
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
Diffusional effects on the reversible excited-state proton transfer. From experiments to Brownian dynamics
Alexander V Popov1, Elizabeth-Ann Gould, Michael A Salvitti
1School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA. popov@chemistry.gatech.edu
Physical Chemistry Chemical Physics : PCCP
|July 16, 2011
Summary
This study investigates excited state proton transfer (ESPT) in a complex three-body system. Brownian dynamics simulations and adapted diffusion models accurately describe proton mobility and kinetics in non-aqueous solvents.
Area of Science:
- Photochemistry
- Physical Chemistry
- Chemical Dynamics
Background:
- Excited state proton transfer (ESPT) is crucial in photochemistry.
- The "super" photoacid N-methyl 6-hydroxyquinolinium perfluorobutane sulfonate exhibits complex ESPT dynamics.
- Standard models struggle with anisotropic charge distributions and counterion effects.
Purpose of the Study:
- To investigate ESPT from a cationic photoacid to non-aqueous solvents.
- To elucidate the role of counterions in proton transfer dynamics.
- To develop and validate computational models for complex ESPT systems.
Main Methods:
- Picosecond and nanosecond time-resolved fluorescence spectroscopy.
- Extensive Brownian dynamics (BD) simulations of a three-body system.
- Adaptation of the Spherically Symmetric Diffusion Problem (SSDP) for anisotropic forces.
Main Results:
- Formation of a quinolinium zwitterion with anisotropic charge distribution.
- Identification of counterion influence on proton mobility.
- Successful adaptation of SSDP to account for anisotropic potential forces.
Conclusions:
- BD simulations and adapted SSDP provide accurate descriptions of the three-body ESPT system.
- The study offers a refined understanding of ESPT mechanisms in complex environments.
- This work advances the modeling of photochemical reactions involving ions and solvents.
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