稀土杂多酸盐对结晶紫光学性质的影响

Effects of Rare Earth Polyoxometalates on Optical Properties of Crystal Violet

通过吸收光谱、荧光光谱考察了酸性条件下,结晶紫(CV)与稀土杂多酸盐在水溶液中组装体系的光谱性质。结果表明,稀土杂多酸盐的加入导致结晶紫吸收峰明显下降,在长波段有新的吸收峰形成;而二者结合形成的超分子体系荧光强度大大增强,表现出比结晶紫更强的发光活性。具有同样Keggin结构的4种稀土杂多阴离子与结晶紫的作用总体一致,稀土元素不同体系的光活性会表现出一定的差异。实验证实,阳离子表面活性剂CTAB的存在会进一步增强体系的发光活性。三者协同作用,形成了更稳定的杂多阴离子———CV+-CTAB三元超分子体系,而-βCD的存在对稀土杂多酸盐与结晶紫的超分子体系稳定不利。

The spectral properties of rare earth polyoxometalate （POM）-Crystal Violet （CV） systems were studied by absorption spectra and synchronous fluorescence in B-R buffer at pH = 4. 1. The addition of POM decreased the absorbance of CV at 590 nm with the appearance of a new band at 655 nm, which indicated the formation of POM-CV complex. Synchronous fluorescence showed that the addition of POM could enhance the fluorescence intensity of CV, which was explained in terms of the hindrance of the formation of the nonfluorescent twisted intramolecular charge transfer（TICT） states of CV by the assembled POM-CV system, and the surfactant CTAB could enhance the luminescence by coordinated assembly.