State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science , Fudan University , Shanghai 200434 , P. R. China.
Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research) , 2 Fusionopolis Way , Innovis, Singapore 138634 , Singapore.
ACS Appl Mater Interfaces. 2019 Feb 13;11(6):6302-6314. doi: 10.1021/acsami.8b19672. Epub 2019 Feb 4.
Configuration-controllable E/Z isomers based on tetraphenylethene were prepared with a facile and effective method. First, compounds 1 and 2, configuration-controllable precursors of E/Z isomers, were synthesized. Then, pure E/Z isomers were obtained via Suzuki reaction, avoiding the difficulties of separation. The conformational changes of E/Z isomers can occur through photoactivation. Importantly, red-shifts of 66 nm from 6 (E-) to 3 (Z-) and 58 nm from 7 (E-) to 4 (Z-) were observed remarkably on the photoluminescence (PL) emission spectra. The Z isomer showed a longer fluorescence lifetime compared with the E isomer. The Z isomers 3 and 4 exhibited piezofluorochromism under grinding, whereas the E isomers 6 and 7 showed no such behaviors. The E isomer has better thermal stability than the Z isomer. Lastly, graphene-like molecules were synthesized with the FeCl/CHNO system. The E and Z isomers after oxidation showed negligible differences in the PL emission spectra because the effective conjugated lengths of oxidized E and Z isomers were both extended. Furthermore, the fabricated field-effect transistors showed nice performance with mobilities of 0.92 and 1.14 cm V s at low operating voltages, respectively.
基于四苯乙烯的构型可控 E/Z 异构体通过一种简单有效的方法制备。首先，合成了 E/Z 异构体的构型可控前体化合物 1 和 2。然后，通过 Suzuki 反应得到了纯的 E/Z 异构体，避免了分离的困难。E/Z 异构体可以通过光活化发生构象变化。重要的是，在光致发光（PL）发射光谱中观察到 6（E-）到 3（Z-）的红移 66nm 和 7（E-）到 4（Z-）的红移 58nm。Z 异构体的荧光寿命比 E 异构体长。Z 异构体 3 和 4 在研磨下表现出压致变色，而 E 异构体 6 和 7 则没有这种行为。Z 异构体的热稳定性比 E 异构体差。最后，用 FeCl/CHNO 体系合成了类石墨烯分子。氧化后的 E 和 Z 异构体在 PL 发射光谱中表现出几乎没有差异，因为氧化后的 E 和 Z 异构体的有效共轭长度都得到了延长。此外，所制备的场效应晶体管在低工作电压下分别表现出 0.92 和 1.14cm^2V^-1s^-1 的良好性能。
