基于跃迁偶极矩取向特征研究乙醚溶液中分子的各向异性度

利用偏振荧光光谱和偏振激发光谱研究了乙醚溶液中荧光分子跃迁偶极距的取向特征.实验结果表明,在垂直线偏振光照射下,乙醚溶液发射出峰值位于305 nm的荧光谱,对应的最佳激励光波长为256 nm.由偏振激发光谱分析得到荧光体的吸收跃迁偶极矩和发射跃迁偶极矩间夹角α的变化规律,揭示了荧光去偏振过程：在粘性溶液中的荧光分子具有一定的偶极取向,α随激发光波长发生变化,当激发波长接近最佳激发光波长时,吸收跃迁偶极矩和发射跃迁偶极矩间趋于平行,荧光的退偏效果较弱,偏振度最大.研究结果能为分子空间取向特征的理论研究提供参考.

The Anisotropy of Ether Solution Based on The Orientation Character of Dipole Transition Moment

The orientation character of dipole transition moment of ether solution was studied by polarization fluorescence spectrum and polarization excitation spectrum,in which there is a fluorescence peak at 305nm whose optimal excitation wavelength is 256 nm.According to the polarization excitation spectrum,the change rule of the angle α between the fluorophore′s absorption transition moment and emission transition moment is obtained,and then the process of fluorescence depolarization is uncovered:the fluorescence molecule has a certain orientation in a highly viscous solution; the angle α is changing with different excitation wavelengths,as the more the excitation light is close to the optimal excitation wavelength,the more the absorption transition moment will parallel closely to emission transition moment which resulted in a weak depolarization and the biggest polarization ratio.The research can provide a reference for the theoretical study on the molecular character.