FORMATION OF MOLECULAR ASSEMBLIES REMPONSIVE TO STIMULI AND ENVIRONMENT THROUGH DYNAMIC SELF-ORGANIZATION OF BIOMOLECULE DERIVATIVES

我们专注于叶酸的自我组装能力。我们设计并合成了具有己基、十一烷基或十八烷基取代基的叶酸衍生物，用于开发功能性热致或溶致介晶材料。这些化合物具有近晶或离散液晶性。它们的相行为在很大程度上取决于烷基链的长度。近晶相和分散相的形成归因于叶酸衍生物的蝶呤环的带状和盘状聚集。三氟甲磺酸钠或十二烷的加入使叶酸衍生物的氢键由带状变为圆盘状。这些结果表明，在分子组装体中的蝶呤环的聚集模式可以通过改变外部条件，如离子-偶极相互作用或介质的介电性来控制从带状到盘状。

We focused on the self-assembling abilities of folic acid. We designed and synthesized folic acid derivatives having hexyl, undecyl, or octadecyl substituents for the development of functional thermotropic or lyotropic mesomorphic materials. These compounds showed smectic or discotic liquid crystallinity. Their phase behavior was greatly dependent on the length of the alkyl chains. The formation of smectic and discotic phases is attributable to ribbon-and disk-like aggregation of pterin rings of folic acid derivatives. The adition of sodium triflate or dodecane to a smecitc liquid-crystalline folic acid derivative lead to the change of the hydrogen-bonded pattern from ribbon to disk. These results indicate that the aggregated pattern of the pterin ring in molecular assemblies can be controlled from ribbon to disks by the change of external conditions such as ion-dipole interactions or hydrophhobicity of the medium.