The synthesis and characterization of six triarylisocyanurates, featuring 2,7-fluorenyl or 9,10-anthracenyl groups incorporated in their peripheral arms are reported. Photophysical studies reveal that these new octupolar derivatives are more fluorescent (ΦF ≥0.60 for all new compounds except for 1,3,5-tri(9H-fluoren-2-yl)-1,3,5-triazinane-2,4,6-trione 3) and present a red-shifted lowest absorption and emission compared to their known phenyl analogues of comparable size. Depending on the nature of the terminal substituent, fast intramolecular energy transfer among the three arms or localization of the excitation on a single branch occurs after population of their first singlet excited state. The latter effect was only observed in the presence of strongly electron-releasing substituents in polar media. These new chromophores are also better two-photon absorbers than the 1,4-phenylene-based isocyanurates reported so far, with cross sections σ2 ≥500 GM at 770 nm for 4-NPh2 the fluorenyl group containing (13) and the anthracenyl group containing (14) chromophores. All these spectroscopic features, analyzed with the help of quantum chemical calculations, are crucial for the design of new biphotonic fluorescent dyes.

中文翻译：

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基于三芳基异氰脲酸酯的荧光双光子吸收剂。

据报道六种三芳基异氰脲酸酯的合成和表征，其特征是在其外围臂中引入了2,7-芴基或9,10-蒽基。光物理研究表明，除了1,3,5-tri（9H-fluoren-2-yl）-1,3,5-triazinane-2,4,1,3,5-tri（9H-fluoren-2-yl）-1,3,5-triazinane-2,4，这些新的八极衍生物均具有更高的荧光性（ΦF≥0.60对于所有新化合物）， 6-三酮3），与已知的类似尺寸的苯基类似物相比，红移的吸收和发射最低。取决于末端取代基的性质，在三个臂之间的快速分子内能量转移或激发在单个分支上的定位发生在它们的第一单线态激发态填充之后。仅在极性介质中存在强烈释放电子的取代基时才观察到后者的作用。这些新的生色团也比迄今为止报道的基于1,4-亚苯基的异氰脲酸酯更好的双光子吸收剂，在770 nm处的σ2≥500GM的横截面，其中4-NPh2的含芴基（13）和蒽基（14）发色团。所有这些光谱特征，借助量子化学计算进行分析，对于新型双光子荧光染料的设计至关重要。