@article{WessigFreyseSchusteretal.2020,
  author    = {Wessig, Pablo and Freyse, Daniel and Schuster, David and Kelling, Alexandra},
  title     = {Fluorescent dyes with large stokes shifts based on Benzo[1,2-d:4,5-d']bis([1,3]dithiole) ("S4-DBD Dyes")},
  series = {Europan journal of organic chemistry},
  volume    = {2020},
  journal   = {Europan journal of organic chemistry},
  number    = {11},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.202000093},
  pages     = {1732 -- 1744},
  year      = {2020},
  abstract  = {We report on a further development of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes by replacement of the four oxygen atoms of the heterocyclic core by sulfur atoms. This variation causes striking changes of the photophysical properties. Whereas absorption and emission significantly shifted to longer wavelength, the fluorescence lifetimes and quantum yields are diminished compared to DBD dyes. The latter effect is presumably caused by an enhanced intersystem crossing to the triplet state due to the sulfur atoms. The very large Stokes shifts of the S-4-DBD dyes ranging from 3000 cm(-1) to 7400 cm(-1) (67 nm to 191 nm) should be especially emphasized. By analogy with DBD dyes a broad variation of absorption and emission wavelength is possible by introducing different electron withdrawing substituents. Moreover, some derivatives for coupling with biomolecules were developed.},
  language  = {en}
}
@article{WessigJohnSperlichetal.2020,
  author    = {Wessig, Pablo and John, Leonard and Sperlich, Eric and Kelling, Alexandra},
  title     = {Sulfur tuning of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes},
  series = {European journal of organic chemistry},
  volume    = {2021},
  journal   = {European journal of organic chemistry},
  number    = {3},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.202001418},
  pages     = {499 -- 511},
  year      = {2020},
  abstract  = {The replacement of oxygen by sulfur atoms of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes is an efficient way to adjust the photophysical properties (sulfur tuning). While previously developed S-4-DBD dyes exhibit considerably red-shifted absorption and emission wavelength, the heavy atom effect of four sulfur atoms cause low fluorescence quantum yields and short fluorescence lifetimes. Herein, we demonstrate that the replacement of less than four sulfur atoms (S-1-DBD, 1,2-S-2-DBD, and 1,4-S-2-DBD dyes) permits a fine-tuning of the photophysical properties. In some cases, a similar influence on the wavelength without the detrimental effect on the quantum yields and lifetimes is observed. Furthermore, the synthetic accessibility of S-1- and S-2-DBD dyes is improved, compared with S-4-DBD dyes. For coupling with biomolecules a series of reactive derivatives of the new dyes were developed (azides, OSu esters, alkynes, maleimides).},
  language  = {en}
}