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Ultrafast Dynamics of Long Homologues of Carotenoid Zeaxanthin

Staleva, Hristina; Zeeshan, Muhammad; Chabera, Pavel LU ; Partali, Vassilia; Sliwka, Hans-Richard and Polivka, Tomas (2015) In The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory 119(46). p.11304-11312
Abstract
Three zeaxanthin homologues with conjugation lengths N of 15, 19, and 23 denoted as Z15, Z19, and Z23 were studied by femtosecond transient absorption spectroscopy, and the results were compared to those obtained for zeaxanthin (Z11). The energies of S2 decrease from 20 450 cm(-1) (Z11) to 18 280 cm(-1) (Z15), 17?095 cm(-1) (Z19), and 16?560 cm(-1) (Z23). Fitting the N dependence of the S-2 energies allowed the estimation of [Formula: see text], the S-2 energy of a hypothetical infinite zeaxanthin, to be similar to 14?000 cm(-1). Exciting the 0-0 band of the S-2 state produces characteristic S-1-S-n spectral profiles in transient absorption spectra with maxima at 556 nm (Z11), 630 nm (Z15), 690 nm (Z19), and 740 nm (Z23). The red shift of... (More)
Three zeaxanthin homologues with conjugation lengths N of 15, 19, and 23 denoted as Z15, Z19, and Z23 were studied by femtosecond transient absorption spectroscopy, and the results were compared to those obtained for zeaxanthin (Z11). The energies of S2 decrease from 20 450 cm(-1) (Z11) to 18 280 cm(-1) (Z15), 17?095 cm(-1) (Z19), and 16?560 cm(-1) (Z23). Fitting the N dependence of the S-2 energies allowed the estimation of [Formula: see text], the S-2 energy of a hypothetical infinite zeaxanthin, to be similar to 14?000 cm(-1). Exciting the 0-0 band of the S-2 state produces characteristic S-1-S-n spectral profiles in transient absorption spectra with maxima at 556 nm (Z11), 630 nm (Z15), 690 nm (Z19), and 740 nm (Z23). The red shift of the S-1-S-n transition with increasing conjugation length is caused by a decrease in the S-1 state energy, resulting in S-1 lifetimes of 9 ps (Z11), 0.9 ps (Z15), 0.35 ps (Z19), and 0.19 ps (Z23). Essentially the same lifetimes were obtained after excess energy excitation at 400 nm, but S-1-S-n becomes broader, indicating a larger conformation disorder in the S-1 state after 400 nm excitation compared to excitation into the 0-0 band of the S-2 state. An S* signal was observed in all samples, but only for Z15, Z19, and Z23 does the S* signal decay with a lifetime different from that of the S-1 state. The S* lifetimes are 2.9 and 1.6 ps for Z15 and Z19, respectively. In Z23 the S* signal needs two decay components yielding lifetimes of 0.24 and 2.3 ps. The S* signal is more pronounced after 400 nm excitation (Less)
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organization
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Contribution to journal
publication status
published
subject
in
The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory
volume
119
issue
46
pages
11304 - 11312
publisher
The American Chemical Society
external identifiers
  • wos:000365462800008
  • scopus:84947997293
ISSN
1520-5215
DOI
10.1021/acs.jpca.5b08460
language
English
LU publication?
yes
id
24fe6d29-141c-43c1-89a7-fc67a54725c8 (old id 8525865)
date added to LUP
2016-01-20 14:59:58
date last changed
2017-09-10 04:18:05
@article{24fe6d29-141c-43c1-89a7-fc67a54725c8,
  abstract     = {Three zeaxanthin homologues with conjugation lengths N of 15, 19, and 23 denoted as Z15, Z19, and Z23 were studied by femtosecond transient absorption spectroscopy, and the results were compared to those obtained for zeaxanthin (Z11). The energies of S2 decrease from 20 450 cm(-1) (Z11) to 18 280 cm(-1) (Z15), 17?095 cm(-1) (Z19), and 16?560 cm(-1) (Z23). Fitting the N dependence of the S-2 energies allowed the estimation of [Formula: see text], the S-2 energy of a hypothetical infinite zeaxanthin, to be similar to 14?000 cm(-1). Exciting the 0-0 band of the S-2 state produces characteristic S-1-S-n spectral profiles in transient absorption spectra with maxima at 556 nm (Z11), 630 nm (Z15), 690 nm (Z19), and 740 nm (Z23). The red shift of the S-1-S-n transition with increasing conjugation length is caused by a decrease in the S-1 state energy, resulting in S-1 lifetimes of 9 ps (Z11), 0.9 ps (Z15), 0.35 ps (Z19), and 0.19 ps (Z23). Essentially the same lifetimes were obtained after excess energy excitation at 400 nm, but S-1-S-n becomes broader, indicating a larger conformation disorder in the S-1 state after 400 nm excitation compared to excitation into the 0-0 band of the S-2 state. An S* signal was observed in all samples, but only for Z15, Z19, and Z23 does the S* signal decay with a lifetime different from that of the S-1 state. The S* lifetimes are 2.9 and 1.6 ps for Z15 and Z19, respectively. In Z23 the S* signal needs two decay components yielding lifetimes of 0.24 and 2.3 ps. The S* signal is more pronounced after 400 nm excitation},
  author       = {Staleva, Hristina and Zeeshan, Muhammad and Chabera, Pavel and Partali, Vassilia and Sliwka, Hans-Richard and Polivka, Tomas},
  issn         = {1520-5215},
  language     = {eng},
  number       = {46},
  pages        = {11304--11312},
  publisher    = {The American Chemical Society},
  series       = {The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory},
  title        = {Ultrafast Dynamics of Long Homologues of Carotenoid Zeaxanthin},
  url          = {http://dx.doi.org/10.1021/acs.jpca.5b08460},
  volume       = {119},
  year         = {2015},
}