Novikov V S, Kuzmin V V, Kuznetsov S M, Darvin M E, Lademann J, Sagitova E A, Ustynyuk L Yu, Prokhorov K A, Nikolaeva G Yu
Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov St., 119991 Moscow, Russia.
Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov St., 119991 Moscow, Russia.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Jul 5;255:119668. doi: 10.1016/j.saa.2021.119668. Epub 2021 Mar 9.
We carried out calculations of non-resonance Raman spectra of ß-carotene and polyenes CH(CHCH)CHCH 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.
我们使用密度泛函理论（DFT）对β-胡萝卜素和多烯CH(CHCH)CHCH的非共振拉曼光谱进行了计算。我们发现，C═C和C─C伸缩带的峰位和强度取决于多烯链的长度和异构体的类型。我们测得的β-胡萝卜素粉末的非共振拉曼光谱与全反式β-胡萝卜素的DFT模拟拉曼光谱匹配良好。结果表明，β-胡萝卜素的C═C和C─C伸缩带在共振拉曼光谱和非共振拉曼光谱中的峰位和相对强度相似。多烯结构中共轭双键数量（n = 3 - 30）的增加会导致最强的C═C和C─C带的位置随着带强度的增加而单调地向低波数移动。异构体数量的增加会导致具有9、10、11、15和24个双键的多烯的C─C伸缩带强度单调降低。异构体数量的增加会不均匀地影响C─C伸缩带的形状、位置和强度。
