title: Effect of Isomerization on Excited-State Dynamics of Carotenoid Fucoxanthin.
abstract: Ultrafast transient absorption spectroscopy and single-wavelength anisotropy measurements were used to study the effect of isomerization on the excited-state properties of fucoxanthin in polar and nonpolar solvents. The excitation wavelengths were 477 nm for all-trans-fucoxanthin, and 333 and 477 nm for cis-fucoxanthin. All transient absorption spectra of the fucoxanthin isomers in polar solvents show intramolecular charge transfer (ICT) state features, typical for carbonyl carotenoids. Global analysis of the data requires an additional fitting component, originated from the presence of blue and red forms of fucoxanthin in a polar protic solvent. Here we demonstrate that the ICT state decays faster than the S1state, due to the significant contribution of the red form to the ICT state dynamics. The isomerization does not affect the S1lifetime, but induces a larger difference between the S1- and ICT-state lifetimes in cis-fucoxanthin, which is likely caused by alterations of ICT coupling to either the S1or S0states; the S*-state signal is more pronounced for cis-isomers in a nonpolar solvent.
authors.affiliation: Institute of Physics and Biophysics, Faculty of Science, University of South Bohemia , Branišovská 1760, 37005 České Budějovice, Czech Republic.
authors.forename: Valentyna
authors.initials: V
authors.lastname: Kuznetsova
authors.affiliation: Division of Chemical Physics, Lund University , P.O. Box 124, Lund SE-22100, Sweden.
authors.forename: Pavel
authors.initials: P
authors.lastname: Chábera
authors.affiliation: Institute of Physics and Biophysics, Faculty of Science, University of South Bohemia , Branišovská 1760, 37005 České Budějovice, Czech Republic.|Institute of Plant Molecular Biology, Biological Centre, Czech Academy of Sciences , 37005 České Budějovice, Czech Republic.
authors.forename: Radek
authors.initials: R
authors.lastname: Litvín
authors.affiliation: Institute of Physics and Biophysics, Faculty of Science, University of South Bohemia , Branišovská 1760, 37005 České Budějovice, Czech Republic.|Institute of Plant Molecular Biology, Biological Centre, Czech Academy of Sciences , 37005 České Budějovice, Czech Republic.
authors.forename: Tomáš
authors.identifier: 0000-0002-6176-0420
authors.initials: T
authors.lastname: Polívka
authors.affiliation: Institute of Physics and Biophysics, Faculty of Science, University of South Bohemia , Branišovská 1760, 37005 České Budějovice, Czech Republic.
authors.forename: Marcel
authors.identifier: 0000-0002-0004-528X
authors.initials: M
authors.lastname: Fuciman
mesh_terms: D015394:Molecular Structure; D011789:Quantum Theory; D013237:Stereoisomerism; D024341:Xanthophylls / Q000737:chemistry*
chemical_list: D024341:Xanthophylls; C025164:fucoxanthin