Papadopoulos Julian, Merkens Kay, Müller Thomas J J
Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
Chemistry. 2018 Jan 19;24(4):974-983. doi: 10.1002/chem.201704912. Epub 2017 Dec 13.
Novel E-configured coumarin-based merocyanines were efficiently synthesized by a one-pot, three-component Sonogashira coupling-Michael addition starting from triflyl coumarins, terminal alkynes and secondary amines. The photophysical properties of the synthesized yellow to orange merocyanines were studied by UV/Vis and fluorescence spectroscopy and rationalized by Hammett-Taft correlations and DFT and TD-DFT calculations. Most compounds were only weakly fluorescent in solution; however, two compounds were investigated in more detail with respect to their aggregation behavior. The system for R =H and NR =pyrrolidinyl shows aggregation induced emission at a water content of 40-60 % in methanol, while the chromophore with R =p-Me NC H and NR =morpholinyl displays considerable aggregation induced emission enhancement with a concomitant redshift at increasing water contents in THF.
以三氟甲磺酸香豆素、末端炔烃和仲胺为原料，通过一锅法、三组分Sonogashira偶联-迈克尔加成反应高效合成了新型E-构型香豆素基部花青。通过紫外/可见光谱和荧光光谱研究了合成的黄色至橙色部花青的光物理性质，并通过哈米特-塔夫脱相关性以及密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）计算进行了合理化分析。大多数化合物在溶液中仅具有微弱荧光；然而，对两种化合物的聚集行为进行了更详细的研究。R = H且NR = 吡咯烷基的体系在甲醇中水含量为40-60%时表现出聚集诱导发光，而R = p-MeNC6H4且NR = 吗啉基的发色团在四氢呋喃中水含量增加时显示出显著的聚集诱导发光增强以及伴随的红移。
