Paul Saurav, Chakraborty Bimal Bhushan, Rao Nandiraju V S, Choudhury Sudip
Department of Chemistry, Assam University, Silchar 788011, India.
Centre for Soft Matter, Department of Chemistry, Assam University, Silchar 788011, India.
Materials (Basel). 2024 Jul 20;17(14):3587. doi: 10.3390/ma17143587.
Aggregation-induced emitters or AIEgens are generally signified by their stronger photoluminescence in aggregation than in the solution state. Due to high emission efficiency in aggregate and solid states and good processability, organic AIEgens drew attention to the development of advanced luminescent materials. However, as mesogenic materials self-assemble to a different molecular arrangement in different phases, achieving liquid crystallinity and AIE properties in the same molecule would provide a valuable tool to develop solvent-independent AIEgenic materials. With this goal, the present work reports the synthesis of new organic thermotropic liquid crystalline compounds exhibiting aggregation-induced emission (AIE). The synthesized compounds exhibit strong green luminescence in a solid state which sharply quenches upon entering smectic mesophase by heating. This is in addition to the exhibition of dispersion medium (solvent)-dependent emission, thus providing a dual mode of AIE. The mesogenic property of the synthesized compounds was studied by XRD, POM, and DSC. The AIE was studied by fluorescence spectroscopy and variable temperature fluorescence microscopy. A DFT study was carried out to gain an insight into the AIEgenic behavior of the material.
聚集诱导发光体或聚集诱导发光材料（AIEgens）通常表现为在聚集态下比在溶液态下具有更强的光致发光。由于在聚集态和固态下具有高发射效率以及良好的可加工性，有机AIEgens在先进发光材料的开发中受到关注。然而，由于介晶材料在不同相中自组装成不同的分子排列，在同一分子中实现液晶性和AIE性质将为开发与溶剂无关的AIEgenic材料提供一个有价值的工具。出于这个目标，本工作报道了新型有机热致液晶化合物的合成，这些化合物表现出聚集诱导发光（AIE）。合成的化合物在固态下呈现强烈的绿色发光，加热进入近晶相时会急剧猝灭。此外，还表现出与分散介质（溶剂）相关的发射，从而提供了一种双重模式的AIE。通过X射线衍射（XRD）、偏光显微镜（POM）和差示扫描量热法（DSC）研究了合成化合物的介晶性质。通过荧光光谱和变温荧光显微镜研究了AIE。进行了密度泛函理论（DFT）研究以深入了解该材料的AIEgenic行为。
