Relaxation dynamics of high-energy excited states of carotenoids studied by UV excitation and pump-repump-probe transient absorption spectroscopy

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60076658%3A12310%2F23%3A43906676" target="_blank" >RIV/60076658:12310/23:43906676 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlelanding/2023/CP/D3CP02485G" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2023/CP/D3CP02485G</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d3cp02485g" target="_blank" >10.1039/d3cp02485g</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Relaxation dynamics of high-energy excited states of carotenoids studied by UV excitation and pump-repump-probe transient absorption spectroscopy

Popis výsledku v původním jazyce

The excited states of carotenoids have been a subject of numerous studies. While a majority of these reports target the excited state dynamics initiated by the excitation of the S-2 state, the upper excited state(s) absorbing in the UV spectral region (denoted as S-UV) has been only scarcely studied. Moreover, the relation between the S-UV and S-n, the final state of the well-known S-1-S-n transition of carotenoids, remains unknown. To address this yet-unresolved issue, we compared the excited state dynamics of two carotenoids, namely, &amp; beta;-carotene and astaxanthin, after excitation of either the S-UV or S-n state. The S-UV state was excited directly by UV light, and the excitation of the S-n state was achieved via re-pumping the S-1-S-n transition. The results indicated that direct S-UV excitation produces an S-1-S-n band that is significantly broader than that obtained after S-2 excitation, most probably due to the generation of multiple S-1 conformations produced by excess energy. No such broadening is observed if the S-n state is excited by the re-pump pulse. This shows that the S-n and S-UV states are different, each initializing a specific relaxation pathway. We propose that the S-n state retains the coupled triplet pair character of the S-1 state, while the S-UV state is the higher state of Bu+ symmetry accessible by one-photon transition.

Název v anglickém jazyce

Relaxation dynamics of high-energy excited states of carotenoids studied by UV excitation and pump-repump-probe transient absorption spectroscopy

Popis výsledku anglicky

The excited states of carotenoids have been a subject of numerous studies. While a majority of these reports target the excited state dynamics initiated by the excitation of the S-2 state, the upper excited state(s) absorbing in the UV spectral region (denoted as S-UV) has been only scarcely studied. Moreover, the relation between the S-UV and S-n, the final state of the well-known S-1-S-n transition of carotenoids, remains unknown. To address this yet-unresolved issue, we compared the excited state dynamics of two carotenoids, namely, &amp; beta;-carotene and astaxanthin, after excitation of either the S-UV or S-n state. The S-UV state was excited directly by UV light, and the excitation of the S-n state was achieved via re-pumping the S-1-S-n transition. The results indicated that direct S-UV excitation produces an S-1-S-n band that is significantly broader than that obtained after S-2 excitation, most probably due to the generation of multiple S-1 conformations produced by excess energy. No such broadening is observed if the S-n state is excited by the re-pump pulse. This shows that the S-n and S-UV states are different, each initializing a specific relaxation pathway. We propose that the S-n state retains the coupled triplet pair character of the S-1 state, while the S-UV state is the higher state of Bu+ symmetry accessible by one-photon transition.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GX19-28323X" target="_blank" >GX19-28323X: Vztah mezi strukturou a funkcí karotenoidů: Nové cesty k řešení nezodpovězených otázek</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

—

Svazek periodika

25

Číslo periodika v rámci svazku

33

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

9

Strana od-do

22336-22344

Kód UT WoS článku

001047562100001

EID výsledku v databázi Scopus

2-s2.0-85168780503