@article{Schwarze2021,
  author    = {Schwarze, Thomas},
  title     = {Determination of Pd2+ by fluorescence enhancement caused by an off-switching of an energy- and an electron transfer},
  series = {ChemistrySelect},
  volume    = {6},
  journal   = {ChemistrySelect},
  number    = {3},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {2365-6549},
  doi       = {10.1002/slct.202003975},
  pages     = {318 -- 322},
  year      = {2021},
  abstract  = {In this paper, we introduce a fluorescent dye 1, which is able to detect selectively Pd2+ by a clear fluorescence enhancement (FE) in THF. In the presence of eight Pd2+ equivalents, we observed a fluorescence enhancement factor (FEF) of 28.3. The high Pd2+ induced FEF can be explained by an off switching of multiple quenching processes within 1 by Pd2+. In the free dye 1 a photoinduced electron transfer (PET) and energy transfer (ET) takes place and quenches the anthracenic fluorescence. The coordination of eight Pd2+ units by the alkylthio-substituted porphyrazine receptor suppresses the PET and ET quenching process and the anthracenic fluorescence is switched on.},
  language  = {en}
}
@article{SchwarzeKellingSperlichetal.2021,
  author    = {Schwarze, Thomas and Kelling, Alexandra and Sperlich, Eric and Holdt, Hans-J{\"u}rgen},
  title     = {Influence of regioisomerism in 9-anthracenyl-substituted dithiodicyanoethene derivatives on photoinduced electron transfer controlled by intramolecular charge transfer},
  series = {ChemPhotoChem},
  volume    = {5},
  journal   = {ChemPhotoChem},
  number    = {10},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {2367-0932},
  doi       = {10.1002/cptc.202100070},
  pages     = {911 -- 914},
  year      = {2021},
  abstract  = {In this paper, we report on the fluorescence behaviour of three regioisomers which consist of two 9-anthracenyl fluorophores and of differently substituted dithiodicyanoethene moieties. These isomeric fluorescent probes show different quantum yields (phi(f)). In these probes, an oxidative photoinduced electron transfer (PET) from the excited 9-anthracenyl fluorophore to the dithiodicyanoethene unit quenches the fluorescence. This quenching process is accelerated by an intramolecular charge transfer (ICT) of the push-pull pi-electron system of the dithiodicyanoethene group. The acceleration of the PET depends on the strength of the ICT unit. The higher the dipole moment of the ICT unit, the stronger the observed fluorescence quenching. To the best of our knowledge, this is the first report of a regioisomeric influence on an oxidative PET by an ICT.},
  language  = {en}
}
@article{ZhaoOpitzEljarratetal.2021,
  author    = {Zhao, Yuhang and Opitz, Andreas and Eljarrat, Alberto and Kochovski, Zdravko and Koch, Christoph and Koch, Norbert and Lu, Yan},
  title     = {Kinetic study on the adsorption of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane on Ag nanoparticles in chloroform},
  series = {ACS applied nano materials},
  volume    = {4},
  journal   = {ACS applied nano materials},
  number    = {11},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {2574-0970},
  doi       = {10.1021/acsanm.1c02153},
  pages     = {11625 -- 11635},
  year      = {2021},
  abstract  = {In this study, the kinetics of the adsorption of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F(4)TCNQ) on the surface of Ag nanoparticles (Ag NPs) in chloroform has been intensively investigated, as molecular doping is known to play a crucial role in organic electronic devices. Based on the results obtained from UV-visible (vis)-near-infrared (NIR) absorption spectroscopy, cryogenic transmission electron microscopy, scanning nanobeam electron diffraction, and electron energy loss spectroscopy, a two-step interaction kinetics has been proposed for the Ag NPs and F(4)TCNQ molecules, which includes the first step of electron transfer from Ag NPs to F(4)TCNQ indicated by the ionization of F(4)TCNQ and the second step of the formation of a Ag-F(4)TCNQ complex. The whole process has been followed via UV-vis-NIR absorption spectroscopy, which reveals distinct kinetics at two stages: the instantaneous ionization and the long-term complex formation. The kinetics and the influence of the molar ratio of Ag NPs/F(4)TCNQ molecules on the interaction between Ag NPs and F(4)TCNQ molecules in an organic solution are reported herein for the first time. Furthermore, the control experiment with silica-coated Ag NPs manifests that the charge transfer at the surface between Ag NPs and F(4)TCNQ molecules is prohibited by a silica layer of 18 nm.},
  language  = {en}
}
@article{SchwarzeMertensMuelleretal.2017,
  author    = {Schwarze, Thomas and Mertens, Monique and Mueller, Peter and Riemer, Janine and Wessig, Pablo and Holdt, Hans-J{\"u}rgen},
  title     = {Highly K+-Selective Fluorescent Probes for Lifetime Sensing of K+ in Living Cells},
  series = {Chemistry - a European journal},
  volume    = {23},
  journal   = {Chemistry - a European journal},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0947-6539},
  doi       = {10.1002/chem.201704368},
  pages     = {17186 -- 17190},
  year      = {2017},
  abstract  = {The new K+-selective fluorescent probes 1 and 2 were obtained by Cu-I-catalyzed 1,3-dipolar azide alkyne cycloaddition (CuAAC) reactions of an alkyne-substituted [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD) ester fluorophore with azido-functionalized N-phenylaza-18-crown-6 ether and N-(o-isopropoxy) phenylaza-18-crown-6 ether, respectively. Probes 1 and 2 allow the detection of K+ in the presence of Na+ in water by fluorescence enhancement (2.2 for 1 at 2000mm K+ and 2.5 for 2 at 160mm K+). Fluorescence lifetime measurements in the absence and presence of K+ revealed bi-exponential decay kinetics with similar lifetimes, however with different proportions changing the averaged fluorescence decay times ((f(av))). For 1 a decrease of (f(av)) from 12.4 to 9.3ns and for 2 an increase from 17.8 to 21.8ns was observed. Variation of the substituent in ortho position of the aniline unit of the N-phenylaza-18-crown-6 host permits the modulation of the K-d value for a certain K+ concentration. For example, substitution of H in 1 by the isopropoxy group (2) decreased the K-d value from >300mm to 10mm. 2 was chosen for studying the efflux of K+ from human red blood cells (RBC). Upon addition of the Ca2+ ionophor ionomycin to a RBC suspension in a buffer containing Ca2+, the fluorescence of 2 slightly rose within 10min, however, after 120min a significant increase was observed.},
  language  = {en}
}