College of Material Science and Engineering, Changchun University of Science and Technology, Changchun, 130022, P. R. China.
Department of Chemistry, Fudan University, Shanghai, 200438, P. R. China.
Chempluschem. 2020 Apr;85(4):711-714. doi: 10.1002/cplu.202000130.
Most synthetic building blocks self-assemble into one- or three-dimensional architectures. However, fewer examples have been reported on the aggregation of amphiphiles to form optically-active two-dimensional (2D) structures. Herein, we report the self-assembly of tetraphenylethylene (TPE)-containing hydrophilic dendrons into 2D sheet structures in aqueous methanol solution. TEM and AFM investigations showed that the self-assembly of disubstituted TPE generates helical nanofibers as an intermediate structure which, in turn, laterally associate into a chiral sheet structure with a thickness of 4.6 nm, whereas tetrasubstituted TPE self-assembles into a nonchiral sheet structure with a thickness of 3.8 nm. In great contrast to the nonchiral sheets, the chiral sheets are able to preferentially absorb the d-enantiomer in a racemic phenylalanine derivative solution accompanied by fluorescence enhancement, thus indicating that the single-layered chiral sheets act as an enantioselective membrane that can be used for fluorescence sensing.
大多数合成建筑块自行组装成一维或三维结构。然而，报道的两亲分子聚集形成光学活性二维（2D）结构的例子较少。在此，我们报告了含有四苯乙烯（TPE）的亲水树枝状大分子在甲醇水溶液中自组装成 2D 片状结构。TEM 和 AFM 研究表明，二取代 TPE 的自组装生成螺旋纳米纤维作为中间结构，进而横向缔合成具有 4.6nm 厚度的手性片状结构，而四取代 TPE 自组装成具有 3.8nm 厚度的非手性片状结构。与非手性片形成鲜明对比的是，手性片能够在手性苯丙氨酸衍生物溶液中优先吸收 d-对映体，并伴有荧光增强，因此表明单层手性片作为手性膜可用于荧光传感。
