TY  - JOUR
A1  - Wessig, Pablo
A1  - Freyse, Daniel
A1  - Schuster, David
A1  - Kelling, Alexandra
T1  - Fluorescent dyes with large stokes shifts based on Benzo[1,2-d:4,5-d']bis([1,3]dithiole) (“S4-DBD Dyes”)
JF  - Europan journal of organic chemistry
N2  - 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.
KW  - fluorescent dyes
KW  - sulfur
KW  - heterocycles
KW  - stokes shift
KW  - photophysics
Y1  - 2020
U6  - https://doi.org/10.1002/ejoc.202000093
SN  - 1434-193X
SN  - 1099-0690
VL  - 2020
IS  - 11
SP  - 1732
EP  - 1744
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - John, Leonard
A1  - Sperlich, Eric
A1  - Kelling, Alexandra
T1  - Sulfur tuning of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes
JF  - European journal of organic chemistry
N2  - 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).
KW  - fluorescent dyes
KW  - heterocycles
KW  - photophysics
KW  - stokes shift
KW  - sulfur
Y1  - 2020
U6  - https://doi.org/10.1002/ejoc.202001418
SN  - 1434-193X
SN  - 1099-0690
VL  - 2021
IS  - 3
SP  - 499
EP  - 511
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wong, Joseph K. -H.
A1  - Ast, Sandra
A1  - Yu, Mingfeng
A1  - Flehr, Roman
A1  - Counsell, Andrew J.
A1  - Turner, Peter
A1  - Crisologo, Patrick
A1  - Todd, Matthew H.
A1  - Rutledge, Peter J.
T1  - Synthesis and Evaluation of 1,8-Disubstituted-Cyclam/Naphthalimide Conjugates as Probes for Metal Ions
JF  - ChemistryOpen : including thesis treasury
N2  - Fluorescent molecular probes for metal ions have a raft of potential applications in chemistry and biomedicine. We report the synthesis and photophysical characterisation of 1,8-disubstituted-cyclam/naphthalimide conjugates and their zinc complexes. An efficient synthesis of 1,8-bis-(2-azidoethyl)cyclam has been developed and used to prepare 1,8-disubstituted triazolyl-cyclam systems, in which the pendant group is connected to triazole C4. UV/Vis and fluorescence emission spectra, zinc binding experiments, fluorescence quantum yield and lifetime measurements and pH titrations of the resultant bis-naphthalimide ligand elucidate a complex pattern of photophysical behaviour. Important differences arise from the inclusion of two fluorophores in the one probe and from the variation of triazole substitution pattern (dye at C4 vs. N1). Introducing a second fluorophore greatly extends fluorescence lifetimes, whereas the altered substitution pattern at the cyclam amines exerts a major influence on fluorescence output and metal binding. Crystal structures of two key zinc complexes evidence variations in triazole coordination that mirror the solution-phase behaviour of these systems.
KW  - chromophores
KW  - click triazoles
KW  - fluorescent probes
KW  - macrocyclic compounds
KW  - photophysics
Y1  - 2016
U6  - https://doi.org/10.1002/open.201600010
SN  - 2191-1363
VL  - 5
SP  - 375
EP  - 385
PB  - Wiley-VCH
CY  - Weinheim
ER  -