White-light-emitting diodes are energy efficiency replacement of conventional lighting sources. Herein, we report the luminescent behavior of three simple cyanostilbenes with triphenylamine-donating groups bearing different electron-withdrawing groups (phenyl, pyridyl, and p-nitrophenyl) in a common donor (D)-π-acceptor (A) α-cyanostilbene construct along with their thermal and electrochemical properties. The density functional theory (DFT) studies reveal that aggregation-induced emission characteristic feature of the D-π-A dyes is inversely proportional to the intramolecular charge transfer (ICT) effect, that is, phenyl-and pyridyl-substituted compounds show characteristic aggregation-induced emission in water, whereas the ICT effect is dominant for the nitro derivative. The extent of ICT and the solvatochromic emission shifts, from blue to red, depend on the strength of the electron-withdrawing group. White luminescence and tunable emission colors are obtained by careful admixtures of these cyanostilbenes bearing triphenylamines. The results rationalized through DFT and time-dependent DFT calculations follow a consistent trend with the energy levels measured from the electrochemical and optical studies. Thermogravimetric analysis and differential scanning calorimetry studies showed excellent thermal stability of the compounds. The scanning electron microscopy and dynamic light scattering measurements were performed to reveal the formation of aggregates. This strategy involving synthetically simple and structurally similar molecules with different emission properties has potential applications in the fabrication of multicolor and white-light-emitting materials.

中文翻译：

---

氰芪和白光发射的发射和颜色调节。

白光发光二极管是传统照明光源的节能替代品。在此，我们报告了三种简单的氰基芪在共同供体（D）-π-受体（A）α-氰基芪结构中的发光行为，其中三苯胺供体基团带有不同的吸电子基团（苯基，吡啶基和对硝基苯基）以及它们的热性能和电化学性能。密度泛函理论（DFT）研究表明，D-π-A染料的聚集诱导发射特征与分子内电荷转移（ICT）效应成反比，即苯基和吡啶基取代的化合物表现出聚集特征水中的诱导排放，而硝基衍生物的ICT效应占主导地位。ICT 和溶剂化变色发射从蓝色到红色的变化程度取决于吸电子基团的强度。通过仔细混合这些带有三苯胺的氰基芪，可以获得白色发光和可调的发射颜色。通过 DFT 和随时间变化的 DFT 计算合理化的结果与电化学和光学研究中测量的能级遵循一致的趋势。热重分析和差示扫描量热研究表明该化合物具有优异的热稳定性。进行扫描电子显微镜和动态光散射测量以揭示聚集体的形成。这种涉及合成简单且结构相似且具有不同发射特性的分子的策略在多色和白光发射材料的制造中具有潜在的应用。