Supramolecular polymeric nanowires: preparation and orthogonal modification of their photophysical properties
作者:Ting Lei、Chu-Yang Cheng、Zi-Hao Guo、Cui Zheng、Ye Zhou、Dehai Liang、Jian Pei
DOI:10.1039/c1jm14138d
日期:——
A series of three-dimensional shape-persistent molecules with three conjugated arms perpendicular to a planar core were developed to self-assemble into supramolecular polymeric nanowires through multiple hydrogen-bonding interactions. After introducing bulky functional groups, aggregation of the nanowires was inhibited, and single molecular nanowires were obtained in concentrated solutions. Therefore, these nanowires had large surface areas with functional groups appended on the surface. Moreover, the photophysical properties of the functional groups including emission peaks and fluorescent lifetime were not changed after self-assembly. Some nanowires emitted high fluorescence after incorporating various chromophores on the side chains of the three-dimensional skeleton through effective fluorescence resonance energy transfer. For example, 1-BTHex showed a quantum efficiency of about 7.9% in solution, similar to the model compound DHBT. However, in the solid state the fluorescence of DHBT was almost quenched with a quantum efficiency lower than 1% due to π–π interactions, but 1-BTHex also gave much higher quantum efficiency, about 6%, which was close to that in solution.
研究人员开发了一系列三维形状持久分子,这些分子具有三个垂直于平面核心的共轭臂,可通过多种氢键相互作用自组装成超分子聚合物纳米线。引入大分子官能团后,纳米线的聚集受到抑制,在浓缩溶液中可获得单分子纳米线。因此,这些纳米线表面附着的官能团具有较大的表面积。此外,功能基团的光物理特性,包括发射峰和荧光寿命,在自组装后没有发生变化。一些纳米线通过有效的荧光共振能量转移,在三维骨架的侧链上加入各种发色团,从而发出高荧光。例如,1-BTHex 在溶液中的量子效率约为 7.9%,与模型化合物 DHBT 相似。然而,在固态下,由于π-π相互作用,DHBT 的荧光几乎被淬灭,量子效率低于 1%,但 1-BTHex 的量子效率也高得多,约为 6%,与溶液中的量子效率接近。