Probing the Aggregation and Signaling Behavior of Some Twisted 9,9′-Bianthryl Derivatives: Observation of Aggregation-Induced Blue-Shifted Emission
Probing the Aggregation and Signaling Behavior of Some Twisted 9,9′-Bianthryl Derivatives: Observation of Aggregation-Induced Blue-Shifted Emission
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DOI：
10.1021/acsomega.8b02232
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发表时间：
2018-11-01
期刊：
影响因子：
4.1
通讯作者：
Sarkar, Moloy
中科院分区：
文献类型：
--
作者：
Banerjee, Somnath;Both, Avinash Kumar;Sarkar, Moloy
为了了解扭曲有机荧光分子在聚集态下的光物理行为，合成了两种扭曲联芳基分子，即9，9 '-联蒽基和10，10'-二氰基-9，9 '-联蒽基，并通过常规的光谱方法对其进行了表征.为了理解C-C键扭曲对联芳基聚集体的光物理响应的作用，还研究了联芳基体系的单芳基对应物（蒽和9-蒽甲腈）。在溶液和聚集态下研究了这些体系的光物理行为沿着它们的单芳基对应物。研究表明，联芳基化合物的荧光光谱显示蓝移发射聚集。有趣的是，对于单芳基聚集体，没有观察到发射的蓝移。与单芳基单元相比，联芳基系统的光物理数据显示，在自组装过程中，几何形状的变化不利于电荷转移态的形成，这最终导致聚集时发射的蓝移。除此之外，这些系统对硝基芳香族炸药的信号的潜力也进行了探索。在所有的硝基芳香族化合物中，最高的荧光猝灭是观察到的硝基酚（如苦味酸（PA））。研究还表明，与单芳基体系相比，联芳基体系对硝基芳烃的荧光猝灭更敏感。Perrin的猝灭球作用模型已被归因于联芳基系统的硝基苯酚（PA）选择性信号传导行为。
With an aim to understand the photophysical behavior of twisted organic fluorescent molecules in their aggregated state, two twisted biaryl molecules, namely, 9,9'-bianthryl and 10,10'-dicyano-9,9'-bianthryl, have been synthesized and characterized by conventional spectroscopic methods. To understand the role of C-C bond twisting on the photophysical response of biaryl aggregates, monoaryl counterparts (anthracene and 9-anthracenecarbonitrile) of the biaryl systems are also investigated. Photophysical behaviors of these systems along with their monoaryl counterpart are investigated in both solution and aggregated state. Investigations reveal that fluorescence spectra of the biaryl compounds show blue-shifted emission upon aggregation. Interestingly, no blue shift of the emission has been observed for monoaryl aggregates. Photophysical data of biaryl systems compared to monoaryl unit reveal that change in geometry, during self-assembly process, disfavors the formation of charge-transfer state, which eventually causes blue shift in the emission upon aggregation. In addition to this, potential of these systems toward signaling of nitroaromatic explosive has also been explored. Among all of the nitroaromatics, the highest fluorescence quenching is observed for nitrophenols (say picric acid (PA)). The investigation also reveals that compared to monoaryl systems, biaryl systems are more responsive to fluorescence quenching by nitroaromatics. Perrin's model of quenching sphere action has been attributed to nitrophenol (PA) selective signaling behavior of biaryl systems.