title: [Temperature characteristics of huang-Ryes factor of all-trans-beta-carotene].
abstract: A visible absorption and Raman spectra of all-trans-beta-beta-carotene was measured in cyclohexanol solution in the temperature range from 68 degrees C to 26 degrees C. The results indicated that the visible absorption spectra are red-shifted, Raman scattering cross section increases, Huang-Ryes factor and electron-phonon coupling constants of CC bond vibration modes decreases with the temperature decreasing. The changes are interpreted using the theory of "coherent weakly damped electronic-lattice vibration model" and "effective conjugation length model". The red shift of the absorption spectra and intensity of the Raman active are attributed to the thermal conformational change-induced increase in the effective conjugation length in all-trans-beta-carotene chains. All-trans-beta-carotene has strong coherent weakly damped CC bonds vibrational properties, which lead to large Raman scattering cross section in the solvent of low temperature. The electron-phonon coupling constants with dimension are used, which can easily establish relation with the Huang-Rhys factor and calculate the electron-phonon coupling constants of CC bond vibration modes. Effective conjugation length, the pi-electron delocalization range and the Raman scattering cross section are described by the electron-phonon coupling constants.
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China. lishuo11@mails.jlu.edu.cn
authors.forename: Shuo
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
authors.forename: Shang
authors.initials: S
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
authors.forename: Zuo-wei
authors.initials: ZW
authors.lastname: Li
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
authors.forename: Guan-nan
authors.initials: GN
authors.lastname: Qu
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
authors.forename: Tian-yuan
authors.initials: TY
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
authors.forename: Cheng-lin
authors.initials: CL
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
authors.forename: Li-mei
authors.initials: LM
authors.lastname: Fan
mesh_terms: D004583:Electrons; D012997:Solvents; D013059:Spectrum Analysis, Raman; D013696:Temperature; D014732:Vibration; D019207:beta Carotene / Q000032:analysis*
chemical_list: D012997:Solvents; D019207:beta Carotene