【摘要】 用紫外 -可见光谱及荧光光谱研究了吸附在TiO2 胶体表面上的两种典型菁染料的光物理性质。吸收光谱表明染料基态分子存在着两种异构体;荧光实验表明TiO2 胶体对菁染料荧光发射强度有增强作用。这是由于染料分子被TiO2 胶体吸附后 ,其分子内的扭转运动受阻 ,从而单重激发态染料分子内扭转运动无辐射跃迁量子效率减少所致。文中还讨论了染料结构对染料 -TiO2 体系荧光发射的影响。更多还原

【Abstract】 The photophysical properties of two typical cyanine dyes, 3,3′ _ diethyl _ 5,5′ _ dimethyl _ selenacarbocyanine bromide and 1,3′ _ diethyl _ 2 _ selenacyanine iodide, adsorbed on the surface of TiO2 colloids have been investigated by UV-visible spectroscopy and fluorescence spectroscopy. It shows there are two kinds of isomers of these dyes in their ground states from UV-visible spectra; Fluorescence experiments show the fluorescence emission intensities of these dyes have been enhanced by TiO2 colloids. These phenomena can be interpreted in terms of reduction of radiationless transition quantum efficiencies of intramolecular torsional motion of 1dye when the dye was adsorbed on TiO2 colloids. The influence of dye structures on the fluorescence emission in dye-TiO2 colloids system was also discussed.更多还原