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

Year: 2015

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

Autors Affiliation: 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.

Journal/Review: JOURNAL OF PHYSICAL CHEMISTRY LETTERS

Volume: 6 (9)      Pages from: 1592  to: 1598

More Information: 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).
KeyWords: 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

Citations: 8
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here