Development of Artificial Materials which Selectively Bind and Separate the Nitrate Ion from Environmental Water

为了开发可用于从环境水中选择性分离硝酸盐离子的人工材料，对环糊精和环寡糖进行吡啶或丁胺基的化学修饰，并对其进行进一步修饰，使其可溶于有机介质或固定化在聚合物上。1)单-[6-（1-吡啶二氧基）-6-脱氧]-环糊精过苯甲酰化得到可溶于氯仿的寄主化合物。宿主结合无机阴离子的能力，包括硝酸盐离子，在氯仿中定量评估。硝酸盐离子与过苯甲酰化宿主的结合比环境水中常见的其他无机阴离子强得多。2)将单-[6-（1-吡啶二氧基）-6-脱氧]-环糊精固定在桥式或悬垂式聚合物上，考察其在水溶液中对硝酸盐离子的吸附。在langmuir型吸附等温线上，硝酸盐离子被吸附在宿主聚合物上。然而，聚合物的最大吸附量小于总暴露在水中的硝酸盐离子。3)将环糊精的C(6)-OH基团全部替换为丁胺基，并在酸性水溶液中考察其与硝酸盐离子的结合能力。宿主-硝酸盐离子体系的结合常数小得令人不满意，尽管它是未修饰的环糊精-硝酸盐离子体系的50倍左右。另一方面，宿主在酸性水溶液中与硫酸盐离子结合非常强烈。

In order to develop artificial materials available for the selective separation of the nitrate ion from environmental water, cyclodextrins, cyclic oligosaccharides, were chemically modified with pyridinio or butylamino groups, and the host compounds were further modified to be solubilized in organic media or to be immobilized on polymers.1) Mono-[6-(1-pyridinio)-6-deoxy]-cyclodextrin was perbenzoylated to give a host compound soluble in chloroform. An ability of the host to bind inorganic anions, including the nitrate ion, was uantitatively evaluted in chloroform. The nitrate ion was bound to the perbenzoylated host much more strongly than other inorganic anions common in environmental water.2) Mono-[6-(1-pyridinio)-6-deoxy]-cyclodextrin was immobilized on bridge type or pendant type polymers, and the adsorption of the nitrate ion on the host polymers was examined in an aqueous solution. The nitrate ion was strongly adsorbed on the host polymers with the Langmuir-type adsorption isotherm. However, the maximum amount of adsorption was less than the polymer are not always exposed to the nitrate ion in water.3) All the C(6)-OH groups of cyclodextrins were replaced with butylamino groups, and an ability of the resulting hosts to bind the nitrate ion was examined in an acidic aqueous solution. The binding constant for a host-nitrate ion system was unsatisfactorily small, though it was about 50 times that for a unmodified cyclodextrin-nitrate ion system. On the other hand, the host bind the sulfate ion very strongly in an acidic aqueous solution.