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Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
Photoisomerization for a model protonated Schiff base in solution: sloped/peaked conical intersection perspective
João Pedro Malhado1, James T Hynes
1Instituto de Física, Universidade de São Paulo, CP 66318, 05314-970 São Paulo, SP, Brazil.
The Journal of Chemical Physics
|December 20, 2012
Summary
The topographical character of conical intersections (CIs) influences photochemical funnel efficiency. This study re-examines solvent effects on protonated Schiff base photoisomerization using CI topography, supporting prior interpretations.
Area of Science:
- Photochemistry
- Chemical Physics
- Theoretical Chemistry
Background:
- Conical intersections (CIs) are crucial for efficient photochemical reactions, acting as funnels for nonadiabatic transitions.
- The topographical character (sloped or peaked) of CIs significantly impacts their efficiency.
- Previous studies suggested solvent effects influence quantum yields in protonated Schiff base (PSB) photoisomerization.
Purpose of the Study:
- To re-examine the solvent influence on PSB photoisomerization quantum yield using the topographical perspective of CIs.
- To connect solvent dynamics to the efficiency of nonadiabatic transitions at CIs.
- To enrich the understanding of solvent effects on photochemical reaction pathways.
Main Methods:
- Utilized a topographical perspective of conical intersections (sloped/peaked).
- Employed an effective branching space description derived from internal and solvent coordinates.
- Re-analyzed generalized Langevin equation/surface hopping results.
Main Results:
- The study supports the original interpretation of solvent effects on PSB photoisomerization quantum yield.
- Dynamical solvent effects were linked to the dominance of nonadiabatic transitions before reaching the CI seam.
- Topographical details of CIs were shown to enrich the understanding of solvent influence.
Conclusions:
- The topographical character of conical intersections is a key factor in understanding photochemical reaction efficiency.
- Solvent dynamics play a significant role in modulating nonadiabatic transitions at CIs.
- This work provides a more detailed topographical insight into solvent effects on photoisomerization.
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