测量了含有9个CC共轭双键的链状多烯类生物分子β胡萝卜素在9种溶剂中的紫外—可见吸收和拉曼光谱.结果表明,β胡萝卜素C—C,CC键拉曼散射截面随溶剂体密度增加而线性增加,其机理是β胡萝卜素分子在体密度大的溶剂中受浮动干扰小,分子结构有序性高,π电子离域扩展,产生强的相干弱阻尼CC键振动,而产生大的拉曼散射截面.密度对分子拉曼散射截面影响研究还没见过报道,本文为多烯类链状分子的光散射理论研究提供了实验线索,也对多烯类链状分子性能研究及光电器件研制有参考价值.
We have measured the UV-visible absorption and Raman spectra of β-carotene which contains 9 CC conjugated double bond polyenes biological molecules in 9 kinds of solvents. The results showed that the Raman scattering cross-section for C— C and C C stretching vibration bands of β-carotene increases linearly with the increase of solvent density. The mechanism is that β-carotene in high density solvent is less affected by perturbation,has higher structure order,more extended π electron delocalization,and stronger coherent weakly damping C—C bond vibration,which results in a large Raman scattering cross section. Studies on the influence of solvent density to molecular Raman cross section have not been reported. This paper is promising as on experimental hint on theoretical study of light scattering,and provides a reference for research of polyenes chain molecules and the development of optoelectronic devices.