Solvation dynamics: Improved reproduction of the time-dependent Stokes shift with polarizable empirical force field chromophore models
JournalPhysical Chemistry Chemical Physics
PublisherRoyal Society of Chemistry
MetadataShow full item record
AbstractThe inclusion of explicit polarization in molecular dynamics simulation has gained increasing interest during the last several years. An understudied area is the role of polarizability in computer simulations of solvation dynamics around chromophores, particularly for the large solutes used in experimental studies. In this work, we present fully polarizable ground and excited state force fields for the common fluorophores N-methyl-6-oxyquinolium betaine and Coumarin 153. While analyzing the solvation responses in water, methanol, and the highly viscous ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate we found that the inclusion of solute polarizability considerably increases the agreement of the obtained Stokes shift relaxation functions with experimental data. Solute polarizability slows down the inertial solvation response in the femtosecond time regime and enables the chromophore to adapt its dipole moment to the environment. Furthermore, the developed chromophore force field reproduces the solute dipole moments in both the electronic ground and excited state in environments ranging from gas phase to highly polar media correctly. Based on these studies it is anticipated that polarizable models of chromophores will lead to an improved understanding of the relationship of their environment to their spectroscopic properties.
SponsorsE. H. is recipient of a DOC Fellowship of the Austrian Academy of Sciences at the Institute of Computational Biological Chemistry. Funding by the Austrian Science Fund FWF in the context of Project No. FWF-P28556-N34 to S. S. and from the National Institutes of Health (GM131710) to A. D. M. are acknowledged.
Identifier to cite or link to this itemhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85070956007&doi=10.1039%2fc9cp03000j&partnerID=40&md5=de269f3cb83d86d381d8328bb9016686; http://hdl.handle.net/10713/10513