Photo-control of Separation and Determination of Metal Ion using Micelle Solutions Containing Crowned Spirobenzopyran Derivatives

研究了以十二烷基硫酸酯为表面活性剂，含有含冠醚和十八基的螺苯并吡喃衍生物的胶束溶液在不同金属离子存在下的荧光光谱。在碱性条件下，锂离子的加入使含单氮杂-12-冠-4的螺苯并吡喃类化合物的相对荧光强度显著增强。当分别加入钠离子和钾离子时，含有单氮杂-15-冠-5和-18-冠-6的螺苯并吡喃衍生物的相对荧光强度也得到了最大的增加，这两个离子分别与这些冠醚基团形成了最稳定的络合物。确定阴离子表面活性剂和冠醚螺苯并吡喃组成的胶束的形状和临界胶束浓度(CMC)等基本性质，对于表面活性剂作为胶束组成和有机分子捕捉剂的分子设计是非常重要的。从这个角度出发，测定了含有单氮杂-12-冠-4的螺苯并吡喃冠醚的胶束在黑暗和光照条件下的临界胶束浓度。CMC的大小顺序为：无冠螺苯并吡喃；在可见光照射下，含冠螺苯并吡喃；暗条件下，含冠螺苯并吡喃。胶束聚集数的增加与CMC的趋势相反。动态光散射和透射电子显微镜的观察表明，胶束呈球形，且球形直径随光照射的变化而变化。此外，在光照射下，胶束对有机物的溶解能力也随着胶束极性的变化而变化。

Fluorescence spectra of the micelle solutions, which consist of dodecylsulfate as a surfactant, containing spirobenzopyran derivatives bearing a crown ether moiety and an octadecyl group, what we call crowned spirobenzopyran, were investigated on addition of different metal ions. The remarkable increase in relative fluorescence intensity of spirobenzopyran derivative bearing monoaza-12-crown-4 was observed on addition of lithium ion under alkaline conditions. The most increase in the relative fluorescence intensities of spirobenzopyran derivatives bearing monoaza-15-crwn-5 and-18-crown-6 were also realized when added sodium and potassium ions, respectively, which form the most stable complexes with those crown ether moieties.It is very important to determine the basic properties, such as the shape and the critical micelle concentration (cmc), of the micelle composed of anionic surfactant and crowned spirobenzopyran for the molecular design of the surfactant as the constituent of micelle and as the trapping agent for organic molecules. From this point of view, the critical micelle concentrations of the micelle containing crowned spirobenzopyran, which has a monoaza-12-crown-4, were measured under the dark and the light-irradiation conditions. The values of cmc increased in the following order : without crowned spirobenzopyran < with crowned spirobenzopyran under visible-light irradiation < with crowned spirobenzopyran under dark conditions. On the other hand, the aggregation numbers of the micelle were increased in the reverse of the tendency of cmc. It was realized from the observation using the dynamic light scattering and the transmission electron microscope that the micelles have the spherical shape and the spherical diameter is changed by photo-irradiation. Moreover, the dissolving abilities of the micelles for organic compounds were also altered with the change in polarity of the micelle by photo-irradiation.