【摘要】 共振拉曼光谱是研究线性多烯分子的主要分子光谱技术。该技术完美地表征了π电子能隙对C=C,C—C伸缩振动的调制规律。这种调制是通过电子-声子耦合完成的。改变外界环境,能隙调制作用将受到影响。测量了溶剂中β-胡萝卜素分子在温度、压力、溶剂效应、相变等不同环境影响下的吸收光谱、共振拉曼光谱,研究了不同外场对π电子能隙调制C=C,C—C伸缩振动的影响机理及规律。结果表明,在外场影响下,体系的能量降低,π电子能隙(π—π*)减小会使调制增强。即电子-声子耦合增强,使拉曼强度增加,谱线红移。对理解共振拉曼物理过程,认识线性多烯分子的结构,性能有重要意义,对研制优质光电器件也有参考价值。更多还原

【Abstract】 As an important technique to study the linear polyene molecules,Resonance Raman spectroscopy perfectly characterizes the CC vibrations modulated by theπ-electron band gap.This modulation generated by electron-phonon coupling is significantly influenced by external fields.In this paper,we illustrate the dependence of CC vibration modulated byπ-electron in different environments such as temperature,pressure,phase and solvent.The results show that the decrease of system energy and the narrowing ofπ-electron band gap lead to enhancements of the vibrational modulation.Thus,there are enhances of electron-phonon coupling as well as Raman intensity,result of which the spectra red shift.This research is of great significance for a better interpretation on the structural dependence of linear polyene’s spectral properties and physical process of its resonance Raman scattering.The results also serve as an important reference for developing high quality photoelectric devices.更多还原