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

Result code in 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>

Alternative codes found

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

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10403 - Physical chemistry

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

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

Name of the periodical

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

1463-9084

Volume of the periodical

27

Issue of the periodical within the volume

37

Country of publishing house

GB - UNITED KINGDOM

Number of pages

13

Pages from-to

20313-20325

UT code for WoS article

001567307200001

EID of the result in the Scopus database

2-s2.0-105017060863