o-Nitrobenzyl Photolabile Protecting Groups with Red-Shifted Absorption: Syntheses and Uncaging Cross-Sections for One- and Two-Photon Excitation
作者:Isabelle Aujard、Chouaha Benbrahim、Marine Gouget、Odile Ruel、Jean-Bernard Baudin、Pierre Neveu、Ludovic Jullien
DOI:10.1002/chem.200501393
日期:2006.9.6
quantum yields of uncaging associated with cross-sections of 1-50 GM for two-photon absorption. Although the cross-sections for one- and two-photon absorption of o-nitrobenzyl photolabile protecting groups can be readily improved, we emphasize the difficulty in enlarging the corresponding action uncaging cross-sections in view of the observed trend of their quantum yield of uncaging.
我们评估了邻硝基苄基平台,用于设计具有红移吸收的光不稳定保护基,该保护基可在单光子和双光子激发后被光解。报道了建立不同的共轭邻硝基苄基骨架以及改变苄基位置的几种合成途径。相对于参考的4,5-二甲氧基-2-硝基苄基,几种邻硝基苄基衍生物在近紫外范围内表现出大的红移单光子吸收。通过测量模型笼状醚和酯上的紫外可见吸收和稳态荧光发射,研究了单光子激发后的解笼。在整个研究过程中,笼罩的底物在光解后被干净地释放。单光子吸收后的解开量子产率在0.1-1%的范围内。我们观察到,随着邻硝基苄基保护基团最大波长吸收的增加,这些下降。一种基于荧光相关光谱法(FCS)的双光子激发后的新方法用于测量双光子激发的作用解开截面。研究的邻硝基苄基笼状荧光香豆素系列显示的值在0.1-0.01 Goeppert-Mayer(GM)范围内。这样的结果与用于双光子吸收的与1-50 GM的横截面相关的解开的低量子产率相符。尽管邻硝