Synthesis, characterization and spectral properties of new, highly fluorescent, 4-hydroxythiazoles
作者:Richard Kammel、Denisa Tarabová、Oldřich Machalický、Miloš Nepraš、Božena Frumarová、Jiří Hanusek
DOI:10.1016/j.dyepig.2016.01.017
日期:2016.5
Eight substituted 2-aryl-4-hydroxy-5-(2′-hydroxyphenyl)-1,3-thiazoles have been prepared and their fluorescence properties have been investigated under neutral and alkaline conditions in solutions of various organic solvents. From the comparison with analogous 4-hydroxy-2,5-diphenyl-1,3-thiazole it is clear that both in neutral as well as in the deprotonated state the presence of the 2′-hydroxy group
已经制备了八种取代的2-芳基-4-羟基-5-(2'-羟基苯基)-1,3-噻唑,并且已经在中性和碱性条件下在各种有机溶剂的溶液中研究了它们的荧光性质。从与类似的4-羟基-2,5-二苯基-1,3-噻唑的比较中可以明显看出,无论是在中性还是在去质子化状态下,都有2'-羟基存在(2-4次)增强了荧光量子产率(Φ)–最有可能是由于分子内氢键的形成。将吸电子取代基引入2-芳基(2-吡啶基和4-三氟甲基苯基衍生物)可进一步提高Φ最高为0.93(在二恶烷中)。一旦4位羟基去质子化的吸收(Δ大红移λ最大 ≈70纳米)以及发射(Δ λ EM ≈110纳米)发生带和Φ -s通常0.3和0.7之间。根据量子化学计算和光谱结果,两个羟基之间的氢键相互作用是明显的。所有研究化合物的第一个吸收带对应于具有CT特性的π–π * HOMO–LUMO跃迁。