Development of Anion Receptors Utilizing Hydrophobic Space Formed by Dendrimer Structures

在环境和临床分析领域，人们对水介质中痕量阴离子的分析有着强烈的需求。在这方面，我们设计了具有由苄基型树状结构形成的疏水空间的分子，其可以能够在水-膜界面处结合阴离子，产生足够的电响应作为离子选择性电极。从同样的观点出发，本文还合成了可用作阴离子荧光传感器的苯乙炔型高密度树枝状大分子，制备了具有硫脲结合位点的第1 ~ 4代苯甲基树枝状大分子。通过NMR稀释实验，澄清了它们在非极性溶剂中的聚集不足以干扰与阴离子的结合。基于使用紫外-可见光谱法进行的磷酸二氢根阴离子滴定实验，确定了氯仿中的结合常数为10^3 M^<-1>，并且该值对代次的依赖性不大。虽然没有一个树枝状聚合物响应磷酸二氢阴离子作为离子选择性电极使用的PVC膜含有他们，他们表现出足够的响应对硫酸氢根阴离子，这也是众所周知的强hydrate.Dense苯乙炔型树枝状聚合物的第二代成功地通过使用在我们的实验室开发的协议。与第一代六乙炔基苯相比，树枝状聚合物的荧光效率略有降低。由于还开发了树枝状单元的制备，因此为制备这种类型的较大树枝状聚合物设置了阶段。

There have been strong demands from the fields of environmental and clinical analyses to analyze conveniently trace anions dissolved in aqueous media. In this respect, we designed molecules having hydrophobic space formed by the benzyl type dendrimer structure, which may capable of binding anions at the water-membrane interface, producing sufficient electrical response as ion-selective electrodes. From the same points of view, preparation of highly dense dendrimers of phenylacetylene type, which may be used as fluorescence sensors for anions, was also carried out.The benzylic dentrimers of 1st to 4th generations having a thiourea binding site wee prepared. By the NMR dilution experiments, it was clarified that their aggregation in nonpolar solvents was not significant enough to disturb binding with anions. On the basis of the titration experiments with dihydrogenphosphate anion using UV-vis spectroscopy, the binding constants in chloroform were determined to be in the order of 10^3 M^<-1> and the values were not much dependent on the generation. Though none of the dentrimers responded toward dihydrogenphosphate anion as ion-selective electrodes using a PVC membrane containing them, they exhibited sufficient response toward hydrogensulfate anion, which is also known to be strongly hydrated.Dense phenylacetylene type dendrimers of 2nd generation was successfully prepared by using the protocol developed in our laboratory. The fluorescence efficiency of the dendrimer was slightly reduced compared with the 1st generation hexaethynylbenzene. Since the preparation of a dendron unit was also developed, the stage is set for preparation of larger dendrimers of this type.