The self-assembly and chiroptical properties of tetraphenylethylene dicycle tetracholesterol with an AIE effect
| Autor: | Ying-Xue Yuan, Jun Luo, Yan-Song Zheng, Hejin Jiang, Minghua Liu, Jia-Bin Xiong, Ming Hu |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Circular dichroism
Materials science Dicycle Intramolecular cyclization Quantum yield 02 engineering and technology General Chemistry Tetraphenylethylene 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Fluorescence 0104 chemical sciences chemistry.chemical_compound chemistry Materials Chemistry Related research 0210 nano-technology Luminescence |
| Zdroj: | Journal of Materials Chemistry C. 7:8236-8243 |
| ISSN: | 2050-7534 2050-7526 |
| DOI: | 10.1039/c9tc02134e |
| Popis: | The immobilized propeller-like conformation of tetraphenylethylene (TPE) can be used to emit strong circularly polarized luminescence (CPL) light, but the immobilized propeller-like conformation must be resolved. A single-handed helical conformation of TPE units induced by chiral group(s) that do not need resolution can also enable CPL emission, but related research is very rare. In this paper, TPE dicycle tetracholesterol is synthesized which could self-assemble into nano-tubes with a double molecule-layer shell, and which showed a fluorescence quantum yield of >76%. One film composed of nano-tubes displayed an enhanced first positive circular dichroism (CD) effect and emitted strong positive CPL light. A suspension or solution of the TPE dicycle tetracholesterol in DCE had a first negative CD band and negative CPL emission. In contrast, TPE tetracholesterol without intramolecular cyclization self-assembled into very soft “noodle-like” aggregations and showed very weak CD signals and CPL emission. The TPE dicycle tetracholesterol had a large CPL dissymmetric factor (≤3.0 × 10−3), which was 30 times larger than the TPE tetracholesterol without cycles. Due to the strong bisignate band in the CD spectrum of TPE dicycle tetracholesterol and the absence of a helical structure in aggregates, the CD and CPL signals of the TPE dicycle tetracholesterol could be ascribed to the prevailing single-handed propeller-like conformation of TPE units induced by chiral cholesterol groups. |
| Databáze: | OpenAIRE |
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