title: Resonance Raman spectra of carotenoid molecules: influence of methyl substitutions.
abstract: We report here the resonance Raman spectra and the quantum chemical calculations of the Raman spectra for β-carotene and 13,13'-diphenyl-β-carotene. The first aim of this approach was to test the robustness of the method used for modeling β-carotene, and assess whether it could accurately predict the vibrational properties of derivatives in which conjugated substituents had been introduced. DFT calculations, using the B3LYP functional in combination with the 6-311G(d,p) basis set, were able to accurately predict the influence of two phenyl substituents connected to the β-carotene molecule, although these deeply perturb the vibrational modes. This experimentally validated modeling technique leads to a fine understanding of the origin of the carotenoid resonance Raman bands, which are widely used for assessing the properties of these molecules, and in particular in complex media, such as binding sites provided by biological macromolecules.
authors.affiliation: Theoretical Physics Department, Faculty of Physics, Vilnius University , Saulėtekio al. 9, LT-10222 Vilnius, Lithuania.
authors.forename: Mindaugas
authors.initials: M
authors.lastname: Macernis
authors.forename: Denise
authors.initials: D
authors.lastname: Galzerano
authors.forename: Juozas
authors.initials: J
authors.lastname: Sulskus
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kish
authors.forename: Young-Hun
authors.initials: YH
authors.lastname: Kim
authors.forename: Sangho
authors.initials: S
authors.lastname: Koo
authors.forename: Leonas
authors.initials: L
authors.lastname: Valkunas
authors.forename: Bruno
authors.initials: B
authors.lastname: Robert
mesh_terms: D002338:Carotenoids / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011789:Quantum Theory; D013059:Spectrum Analysis, Raman
chemical_list: D002338:Carotenoids