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Title: Conical intersections of free energy surfaces in solution: Effect of electron correlation on a protonated Schiff base in methanol solution

Abstract

The minimum energy conical intersection (MECI) optimization method with taking account of the dynamic electron correlation effect [T. Mori and S. Kato, Chem. Phys. Lett. 476, 97 (2009)] is extended to locate the MECI of nonequilibrium free energy surfaces in solution. A multistate electronic perturbation theory is introduced into the nonequilibrium free energy formula, which is defined as a function of solute and solvation coordinates. The analytical free energy gradient and interstate coupling vectors are derived, and are applied to locate MECIs in solution. The present method is applied to study the cis-trans photoisomerization reaction of a protonated Schiff base molecule (PSB3) in methanol (MeOH) solution. It is found that the effect of dynamic electron correlation largely lowers the energy of S{sub 1} state. We also show that the solvation effect strongly stabilizes the MECI obtained by twisting the terminal C=N bond to become accessible in MeOH solution, whereas the conical intersection is found to be unstable in gas phase. The present study indicates that both electron correlation and solvation effects are important in the photoisomerization reaction of PSB3. The effect of counterion is also examined, and seems to be rather small in solution. The structures of free energy surfacesmore » around MECIs are also discussed.« less

Authors:
; ;  [1]
  1. Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)
Publication Date:
OSTI Identifier:
21559896
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 133; Journal Issue: 6; Other Information: DOI: 10.1063/1.3472033; (c) 2010 American Institute of Physics; Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CHEMICAL BONDS; ELECTRON CORRELATION; FREE ENERGY; ISOMERIZATION; METHANOL; MOLECULES; OPTIMIZATION; PERTURBATION THEORY; PHOTOCHEMISTRY; REACTION KINETICS; SCHIFF BASES; SOLUTES; SOLUTIONS; SOLVATION; SURFACES; THERMODYNAMICS; ALCOHOLS; CHEMICAL REACTIONS; CHEMISTRY; CORRELATIONS; DISPERSIONS; ENERGY; HOMOGENEOUS MIXTURES; HYDROXY COMPOUNDS; IMINES; KINETICS; MIXTURES; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PHYSICAL PROPERTIES; THERMODYNAMIC PROPERTIES

Citation Formats

Mori, Toshifumi, Nakano, Katsuhiro, and Kato, Shigeki. Conical intersections of free energy surfaces in solution: Effect of electron correlation on a protonated Schiff base in methanol solution. United States: N. p., 2010. Web. doi:10.1063/1.3472033.
Mori, Toshifumi, Nakano, Katsuhiro, & Kato, Shigeki. Conical intersections of free energy surfaces in solution: Effect of electron correlation on a protonated Schiff base in methanol solution. United States. https://doi.org/10.1063/1.3472033
Mori, Toshifumi, Nakano, Katsuhiro, and Kato, Shigeki. 2010. "Conical intersections of free energy surfaces in solution: Effect of electron correlation on a protonated Schiff base in methanol solution". United States. https://doi.org/10.1063/1.3472033.
@article{osti_21559896,
title = {Conical intersections of free energy surfaces in solution: Effect of electron correlation on a protonated Schiff base in methanol solution},
author = {Mori, Toshifumi and Nakano, Katsuhiro and Kato, Shigeki},
abstractNote = {The minimum energy conical intersection (MECI) optimization method with taking account of the dynamic electron correlation effect [T. Mori and S. Kato, Chem. Phys. Lett. 476, 97 (2009)] is extended to locate the MECI of nonequilibrium free energy surfaces in solution. A multistate electronic perturbation theory is introduced into the nonequilibrium free energy formula, which is defined as a function of solute and solvation coordinates. The analytical free energy gradient and interstate coupling vectors are derived, and are applied to locate MECIs in solution. The present method is applied to study the cis-trans photoisomerization reaction of a protonated Schiff base molecule (PSB3) in methanol (MeOH) solution. It is found that the effect of dynamic electron correlation largely lowers the energy of S{sub 1} state. We also show that the solvation effect strongly stabilizes the MECI obtained by twisting the terminal C=N bond to become accessible in MeOH solution, whereas the conical intersection is found to be unstable in gas phase. The present study indicates that both electron correlation and solvation effects are important in the photoisomerization reaction of PSB3. The effect of counterion is also examined, and seems to be rather small in solution. The structures of free energy surfaces around MECIs are also discussed.},
doi = {10.1063/1.3472033},
url = {https://www.osti.gov/biblio/21559896}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 6,
volume = 133,
place = {United States},
year = {Sat Aug 14 00:00:00 EDT 2010},
month = {Sat Aug 14 00:00:00 EDT 2010}
}