Ditriphenylenothiophene butterfly-shape liquid crystals. The influence of polyarene core topology on self-organization, fluorescence and photoconductivity
Ditriphenylenothiophene butterfly-shape liquid crystals. The influence of polyarene core topology on self-organization, fluorescence and photoconductivity
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二并苯并噻吩蝶形液晶。多芳烃核拓扑结构对自组装、荧光及光电导性的影响
DOI：
10.1039/d2nj00655c
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发表时间：
2022-05-03
影响因子：
3.3
通讯作者：
Donnio, Bertrand
中科院分区：
文献类型：
--
作者：
Deng, Wen-Jing;Liu, Shuai;Donnio, Bertrand
采用Suzuki-Miyaura交叉偶联反应和Scholl环化脱氢反应，从合适的前体出发，分两步合成了两个系列的区域异构蝶形液晶体系。核心拓扑结构（即位置异构）的介晶性，凝胶自组装，吸收和发光，和电荷传输性能的两套异构体的影响进行了研究和比较。六个稠合π-共轭分子系统地显示柱状六方（Col（hex））的中间相与β-稠合ditriphenylenothioric化合物（DTPTBn）显示更广泛的中间相范围和更高的相变温度比它们的异构体α-对应物（DTPTAn）。所有的ditriphenylenothiophene在有机溶剂中也表现出很强的聚集行为，并且，此外，发现对于β-异构体，良好的有机胶凝能力。同样有趣的是，测得β-异构体的空穴迁移率大于10（-3）cm（2）v（-1）s（-1），比α-异构体高出约10倍。与DFT计算相结合的分子结构的建模表明，β-异构体具有比略微扭曲的α-异构体更平坦和更延伸的π-共轭核，因此更倾向于优化π-π分子间相互作用，与这些异构体观察到的高温中间相和高电荷载流子迁移率一致。最后，这两组化合物在溶液中发射蓝紫色光，并且当在膜中组织时发射基本上红移。HOMO-LUMO能级的DFT计算也与光学测量一致。这种原始的分子设计和简单的合成组合提供了一种有效的方法来获得新的π-扩展的有机，潜在的半导体材料，用于进一步的电子器件研究。
Two series of regio-isomeric butterfly-shaped liquid crystalline systems, based on a ditriphenylenothiophene core (alpha/beta-DTPT) equipped with eight peripheral Long alkoxy chains, were synthesized in two steps by the Suzuki-Miyaura cross-coupling/Scholl cyclo-dehydrogenation reactions tandem from appropriate precursors. The influence of the core topology (i.e. positional isomerism) on the mesomorphism, gelling self-assembly, absorption and Luminescence, and charge-transport properties of both sets of isomers was investigated and compared. The six fused pi-conjugated molecules systematically display columnar hexagonal (Col(hex)) mesophases with beta-fused ditriphenylenothiophene compounds (DTPTBn) showing more extended mesophase ranges and higher phase transition temperatures than their isomeric alpha-counterparts (DTPTAn). All ditriphenylenothiophenes also show strong aggregation behavior in organic solvents, and, in addition, good organic gelling abilities were found for the beta-isomers. Interestingly too, high hole mobility rates greater than 10(-3) cm(2) v(-1) s(-1) were measured for the beta-isomers, which were about 10 times higher than those of the alpha-counterparts. Modeling of the molecular structures combined with DFT calculations showed that the beta-isomers possess flatter and more extended pi-conjugated cores than the slightly distorted oc-isomers, and consequently were more prone to optimize pi - pi intermolecular interactions, in agreement with the high-temperature mesophases and high charge carrier mobilities observed for these isomers. Finally, both sets of compounds emit blue-purple light in solution and the emission is substantially red-shifted when organized in films. DFT calculations of the HOMO-LUMO energy levels were also consistent with the optical measurements. This original molecular design and straightforward synthesis combination provides an efficient way to obtain novel pi-extended organic, potentially semiconductor materials for further electronic device investigations.