DFT study of Raman spectra of polyenes and ß-carotene: Dependence on length of polyene chain and isomer type

V S Novikov; V V Kuzmin; S M Kuznetsov; M E Darvin; J Lademann; E A Sagitova; L Yu Ustynyuk; K A Prokhorov; G Yu Nikolaeva

doi:10.1016/j.saa.2021.119668

DFT study of Raman spectra of polyenes and ß-carotene: Dependence on length of polyene chain and isomer type

Spectrochim Acta A Mol Biomol Spectrosc. 2021 Jul 5:255:119668. doi: 10.1016/j.saa.2021.119668. Epub 2021 Mar 9.

Authors

V S Novikov¹, V V Kuzmin², S M Kuznetsov², M E Darvin³, J Lademann³, E A Sagitova², L Yu Ustynyuk⁴, K A Prokhorov², G Yu Nikolaeva²

Affiliations

¹ Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov St., 119991 Moscow, Russia. Electronic address: vs.novikov@kapella.gpi.ru.
² Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov St., 119991 Moscow, Russia.
³ Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Charitéplatz 1, 10117 Berlin, Germany.
⁴ Chemistry Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1(3), 119991 Moscow, Russia.

PMID: 33761387
DOI: 10.1016/j.saa.2021.119668

Abstract

We carried out calculations of non-resonance Raman spectra of ß-carotene and polyenes CH₂(CHCH)_n-2CHCH₂ using the density functional theory (DFT). We revealed that the peak positions and intensities of the CC and CC stretching bands depend on length of the polyene chain and type of the isomer. Our experimental non-resonance Raman spectra of ß-carotene powder match well the DFT-simulated Raman spectrum of ß-carotene in the all-trans form. The peak positions and relative intensities of the CC and CC stretching bands of ß-carotene turned out to be similar in the resonance and non-resonance Raman spectra. An increase in the number of conjugated double bonds (n = 3-30) in a polyene structure results in a monotonous shift of the positions of the most intense CC and CC bands towards lower wavenumbers with an increase in the band intensities. An increase in the isomer number results in the monotonous decrease of the CC stretching band intensity for polyenes with 9, 10, 11, 15 and 24 double bonds. An increase in the isomer number inhomogeneously influences the form, position and intensity of the CC stretching band.

Keywords: Antioxidants; Carotenoids; Density functional theory; Raman spectroscopy.