Institute of Chemistry of the Polish Academy of Sciences, Warsaw, Poland.
J Phys Chem A. 2012 Oct 4;116(39):9614-20. doi: 10.1021/jp305459r. Epub 2012 Sep 20.
Eight previously inaccessible derivatives of 10-hydroxybenzo[h]quinoline were prepared via a straightforward strategy comprising formation of the benzo[h]quinoline skeleton followed by C-H acetoxylation at position 10. The occurrence of excited state intramolecular proton transfer (ESIPT) was detected in all cases since emission was observed only from the excited keto-tautomer. Studies on derivatives bearing both electron-donating and electron-withdrawing groups adjacent to the pyridine ring allowed us to identify some design patterns giving rise to NIR emission and large Stokes shifts. For a derivative of 10-hydroxybenzo[c]acridine, emission at 745 nm was observed, one of the lowest energy fluorescence ever reported for ESIPT system. On the basis of time-resolved measurements, proton transfer was found to be extremely fast with time constants in the range (0.08-0.45 ps).
通过一种简单的策略，制备了 10-羟基苯并[h]喹啉的 8 种以前无法获得的衍生物，该策略包括形成苯并[h]喹啉骨架，然后在 10 位进行 C-H 乙酰化。由于仅从激发的酮式互变异构体观察到发射，因此所有情况下都检测到了激发态分子内质子转移（ESIPT）的发生。对在吡啶环附近带有供电子和吸电子基团的衍生物的研究使我们能够确定一些设计模式，这些模式可产生近红外发射和大斯托克斯位移。对于 10-羟基苯并[c]吖啶的衍生物，观察到了 745nm 的发射，这是 ESIPT 体系中报道的最低能量荧光之一。基于时间分辨测量，发现质子转移非常快，时间常数在（0.08-0.45 ps）范围内。
