1241912-58-2Relevant academic research and scientific papers
A versatile route to red-emitting carbopyronine dyes for optical microscopy and nanoscopy
Kolmakov, Kirill,Belov, Vladimir N.,Wurm, Christian A.,Harke, Benjamin,Leutenegger, Marcel,Eggeling, Christian,Hell, Stefan W.
experimental part, p. 3593 - 3610 (2010/11/18)
Biological microscopy favors photostable fluorescent markers with large fluorescence quantum yields, low dark triplet state population, good biocompatibility and absorption and emission maxima in the near-infrared, where cellular autofluorescence is minimized. In the present study, carbopyronines absorbing around 640 nm and emitting at around 660 nm, with a low intersystem crossing rate (kisc ≈ 0.5×106 s-1) and excellent properties for cellular imaging were synthesized. A general synthetic route to carbopyronines with functional groups variable in the final steps of the synthesis or in the resulting fluorescent dye is presented. Possessing two 2-me-thoxyethyl groups, the parent dye is soluble in water and most organic solvents. Demethylation of the dye or its precursors is straightforward, clean, and furnishes compounds with one or two 2-hydroxyethyl groups, which can be used for further transformations. Modifications in the linker-containing carboxy group are also possible. A multistep synthesis of the dye starting from a simple precursor and utilizing a single temporary protective group is described. The presented approach may be further applied to the design of caged carbopyronines.
