Identification of the Excited-State C=C and C=O Modes of trans-β-Apo-8′-carotenal with Transient 2D-IR-EXSY and Femtosecond Stimulated Raman Spectroscopy

Anno: 2015

Autori: Di Donato M., Ragnoni E., Lapini A., Kardas TM., Ratajska-Gadomska B., Foggi P., Righini R.

Affiliazione autori: LENS European Lab Non Linear Spect, I-50019 Sesto Fiorentino, Italy; INO, I-50125 Florence, Italy; Univ Firenze, Dipartimento Chim Ugo Schiff, I-50019 Sesto Fiorentino, Italy; Univ Warsaw, Dept Chem, PL-02089 Warsaw, Poland; Univ Perugia, Dipartimento Chim, I-06100 Perugia, Italy.

Abstract: Assigning the vibrational modes of molecules in the electronic excited state is often a difficult task. Here we show that combining two nonlinear spectroscopic techniques, transient 2D exchange infrared spectroscopy (T2D-IR-EXSY) and femtosecond stimulated Raman spectroscopy (FSRS), the contribution of the C=C and C=O modes in the excited-state vibrational spectra of trans-beta-apo-8’carotenal can be unambiguously identified. The experimental results reported in this work confirm a previously proposed assignment based on quantum-chemical calculations and further strengthen the role of an excited state with charge-transfer character in the relaxation pathway of carbonyl carotenoids. On a more general ground, our results highlight the potentiality of nonlinear spectroscopic methods based on the combined use of visible and infrared pulses to correlate structural and electronic changes in photoexcited molecules.

Giornale/Rivista: JOURNAL OF PHYSICAL CHEMISTRY LETTERS

Volume: 6 (9)      Da Pagina: 1592  A: 1598

Maggiori informazioni: We gratefully acknowledge support from the Italian MIUR: project PRIN-2010ERFKXL-004 and program FIRB “Futuro in Ricerca 2010” grant RBFR10Y5VW to M.D.D. and RBFR109ZHQ supporting A.L. and project EFOR-CABIR L. 191/2009 art. 2 comma 44 and funding from LASERLAB-EUROPE (grant agreement no. 284464, EC’s Seventh Framework Programme).
Parole chiavi: Charge transfer; Infrared spectroscopy; Molecules; Pigments; Quantum chemistry; Quantum theory; Raman spectroscopy; Spectroscopic analysis, carotenoids; Electronic excited state; Femtosecond stimulated raman spectroscopies; Nonlinear spectroscopic techniques; photodynamics; Quantum chemical calculations; Raman; vibrations, Excited states
DOI: 10.1021/acs.jpclett.5b00528

Citazioni: 8
dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2025-06-08
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