Synthesis and characterization of various 5′-dye-labeled ribonucleosides

A novel set of visibly coloured dye-labeled 5′-nucleosides, including s-tetrazine (orange), dicyanomethylene-4H-pyran (yellow), benzophenoxazinone (pink), 9,10-anthraquinone (blue) and azobenzene (red) chromophores, were prepared, and their absorption and fluorescence spectra recorded.