Rana Priya, Jennifer G Abigail, Rao T Shanmuka, Mukhopadhyay Sabyasachi, Varathan Elumalai, Das Priyadip
Department of Chemistry, SRM Institute of Science and Technology, SRM Nagar, Potheri, Kattankulathur, Tamil Nadu 603203, India.
Department of Physics, SRM University, Village - Neeru Konda, Guntur, Andhra Pradesh 522240, India.
ACS Omega. 2023 Dec 14;8(51):48855-48872. doi: 10.1021/acsomega.3c06283. eCollection 2023 Dec 26.
Self-assembled nanostructures obtained from various functional π-conjugated organic molecules have been able to draw substantial interest due to their inherent optical properties, which are imperative for developing optoelectronic devices, multiple-color-emitting devices with color-tunable displays, and optical sensors. These π-conjugated molecules have proven their potential employment in various organic electronic applications. Therefore, the stimuli-responsive fabrication of these π-conjugated systems into a well-ordered assembly is extremely crucial to tuning their inherent optical properties for improved performance in organic electronic applications. To this end, herein, we have designed and synthesized a functional π-conjugated molecule () having phenanthro[9,10-]imidazole with terpyridine substitution at the 2 position and its corresponding metal complexes ( and ). By varying the polarity of the self-assembly medium, , , and are fabricated into well-ordered superstructures with morphological individualities. However, this medium polarity-induced self-assembly can tune the inherent optical properties of , , and and generate multiple fluorescence colors. Particularly, this property makes them useful for organic electronic applications, which require adjustable luminescence output. More importantly, in 10% aqueous-THF medium, exhibited H-type aggregation-induced white light emission and behaved as a single-component white light emitter. The experimentally obtained results of the solvent polarity-induced variation in optical properties as well as self-assembly patterns were further confirmed by theoretical investigation using density functional theory calculations. Furthermore, we investigated the - characteristics, both vertical and horizontal, using ITO and glass surfaces coated with , , and , respectively, and displayed maximum current density for the -coated surface with the order of measured current density > > . This observed order of current density measurements was also supported by a direct band gap calculation associated with the frontier molecular orbitals using the Tauc plot. Hence, solvent polarity-induced self-assembly behavior with adjustable luminescence output and superior - characteristics of make it an exceptional candidate for organic electronic applications and electronic device fabrication.
从各种功能性π共轭有机分子获得的自组装纳米结构因其固有的光学性质而引起了广泛关注，这些光学性质对于开发光电器件、具有颜色可调显示器的多色发光器件以及光学传感器至关重要。这些π共轭分子已在各种有机电子应用中证明了其潜在用途。因此，将这些π共轭体系通过刺激响应制备成有序组装体对于调节其固有光学性质以提高有机电子应用中的性能极为关键。为此，在本文中，我们设计并合成了一种功能性π共轭分子（），其在2位具有菲咯[9,10 - ]咪唑并带有三联吡啶取代基及其相应的金属配合物（和）。通过改变自组装介质的极性，、和被制备成具有形态个性的有序超结构。然而，这种介质极性诱导的自组装可以调节、和的固有光学性质并产生多种荧光颜色。特别地，这种性质使其对于需要可调发光输出的有机电子应用很有用。更重要的是，在10%水 - 四氢呋喃介质中，表现出H型聚集诱导的白光发射并作为单组分白光发射体。通过使用密度泛函理论计算的理论研究进一步证实了溶剂极性诱导的光学性质变化以及自组装模式的实验结果。此外，我们分别使用涂有、和的ITO和玻璃表面研究了其垂直和水平的 - 特性，并显示出涂有 - 的表面具有最大电流密度，测量电流密度的顺序为 > > 。使用Tauc图与前沿分子轨道相关的直接带隙计算也支持了观察到的电流密度测量顺序。因此，具有可调发光输出的溶剂极性诱导的自组装行为以及的优异 - 特性使其成为有机电子应用和电子器件制造的杰出候选者。
