We synthesized three different families of quadrupolar dyes, differing by the nature of their aromatic central cores (phenyl, fluorenyl, anthracenyl), in which we systematically varied the length of the π-conjugated backbone and the nature of the central bridge. We compared their linear and non-linear spectroscopic and photophysical features. We showed that the introduction of a diyne bridge is efficient in consistently increasing the Stokes shifts in these fluorophores, especially in high polarity solvents. By a combined theoretical and spectroscopic study we show that this feature is favoured by distortion of their π-conjugated skeleton at the electronic ground state. Unfortunately, this distortion process is generally detrimental to their fluorescence quantum yields. However, in the course of this study, we identify a particularly promising dye, that combines a large two-photon absorption (650 [email protected] nm) while keeping efficient emission (ϕ_f = 0.3) in the far-red/NIR (ca 700 nm) in polar solvent (DMSO).

我们合成了三种不同的四极染料家族，它们的芳香性中心核（苯基，芴基，蒽基）的性质不同，在其中我们系统地改变了π共轭骨架的长度和中心桥的性质。我们比较了它们的线性和非线性光谱和光物理特征。我们表明，引入二炔桥可以有效地持续增加这些荧光团的斯托克斯位移，尤其是在高极性溶剂中。通过组合的理论和光谱学研究，我们表明，此特征受电子基态处其π共轭骨架变形的青睐。不幸的是，这种畸变过程通常不利于它们的荧光量子产率。但是，在这项研究过程中，我们发现了一种特别有前途的染料，极性溶剂（DMSO） 中的远红外/ NIR（约700 nm）中的_f = 0.3 ）。