Vibrational signature of 11B +u and hot 21A −g excited states of carotenoids revisited by femtosecond stimulated Raman spectroscopy

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388971%3A_____%2F25%3A00639462" target="_blank" >RIV/61388971:_____/25:00639462 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/10974938:_____/25:25_88_17 RIV/60076658:12310/25:43909998

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlelanding/2025/cp/d5cp02711j" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2025/cp/d5cp02711j</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d5cp02711j" target="_blank" >10.1039/d5cp02711j</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Vibrational signature of 11B +u and hot 21A −g excited states of carotenoids revisited by femtosecond stimulated Raman spectroscopy

Popis výsledku v původním jazyce

The significance of carotenoids in biological systems cannot be overstated. Their functionality largely arises from unique excited-state dynamics, where photon absorption promotes the molecule to the optically allowed 1(1)B(u)(+) state (conventionally S-2), which rapidly decays to the optically forbidden 2(1)A(g)(-) state (S1). While the vibrational signature of the S-1 state is well established, that of the initial S-2 state has remained elusive. In this work, we identify a consistent S-2-state vibrational signature across five different carotenoids and explain the challenges in isolating this signature. Resonance conditions in the near infrared region cause the S-2 signal to appear as a complex superposition of contributions from stimulated emission to the ground state, excited-state absorption (S2 to Sm), and vibrationally inverted S-1 signals. This results in a mix of positive and negative features that are not trivial to disentangle. After careful analysis, we isolated the genuine S-2 signature, characterized by a C=C stretch near 1600 cm(-1) and a C-C stretch near 1350 cm(-1). The remaining signals originate from the ground or S-1 states but are virtually inseparable from the FSRS signal on S-2-state timescales. Our findings resolve a long-standing spectroscopic challenge and clarify the early excited-state dynamics of carotenoids.

Název v anglickém jazyce

Vibrational signature of 11B +u and hot 21A −g excited states of carotenoids revisited by femtosecond stimulated Raman spectroscopy

Popis výsledku anglicky

The significance of carotenoids in biological systems cannot be overstated. Their functionality largely arises from unique excited-state dynamics, where photon absorption promotes the molecule to the optically allowed 1(1)B(u)(+) state (conventionally S-2), which rapidly decays to the optically forbidden 2(1)A(g)(-) state (S1). While the vibrational signature of the S-1 state is well established, that of the initial S-2 state has remained elusive. In this work, we identify a consistent S-2-state vibrational signature across five different carotenoids and explain the challenges in isolating this signature. Resonance conditions in the near infrared region cause the S-2 signal to appear as a complex superposition of contributions from stimulated emission to the ground state, excited-state absorption (S2 to Sm), and vibrationally inverted S-1 signals. This results in a mix of positive and negative features that are not trivial to disentangle. After careful analysis, we isolated the genuine S-2 signature, characterized by a C=C stretch near 1600 cm(-1) and a C-C stretch near 1350 cm(-1). The remaining signals originate from the ground or S-1 states but are virtually inseparable from the FSRS signal on S-2-state timescales. Our findings resolve a long-standing spectroscopic challenge and clarify the early excited-state dynamics of carotenoids.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

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

1463-9084

Svazek periodika

27

Číslo periodika v rámci svazku

37

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

13

Strana od-do

20313-20325

Kód UT WoS článku

001567307200001

EID výsledku v databázi Scopus

2-s2.0-105017060863