TY - JOUR A1 - Rurack, Knut A1 - Resch-Genger, Ute A1 - Kollmannsberger, M. A1 - Daub, J. A1 - Rettig, W. T1 - Design of an efficient charge-transfer processing molecular system containing a weak electron donor: spectroscopic and redox properties and cation-induced fluorescence enhancement N2 - The acceptor strength of the boron-dipyrromethene chromophore in directly linked donor–acceptor compounds can be tuned by substituents in such a way that a fast excited state charge transfer takes place even for the comparatively weak benzo crown electron donor. This leads to strong fluorescence quenching. Upon binding of cations (Na+ and K+) to the benzo crown receptor, the donor properties of the latter are further reduced, partly suppressing charge transfer. Large fluorescence enhancement factors and cation-selective fluorescence decay times result which are the basis for improved analytical application of these dyes as highly sensitive fluorescent probes. PY - 2000 DO - https://doi.org/10.1016/S0009-2614(00)01058-7 SN - 0009-2614 SN - 1873-4448 VL - 329 IS - 5-6 SP - 363 EP - 369 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-1049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rurack, Knut A1 - Kollmannsberger, M. A1 - Resch-Genger, Ute A1 - Daub, J. T1 - A selective and sensitive fluoroionophore for HgII, AgI, and CuII with virtually decoupled fluorophore and receptor units KW - Fluoreszenz KW - Ionophor PY - 2000 UR - http://pubs.acs.org/journals/jacsat/index.html SN - 0002-7863 SN - 1520-5126 VL - 122 IS - 5 SP - 968 EP - 969 PB - American Chemical Society CY - Washington, DC AN - OPUS4-2092 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kollmannsberger, M. A1 - Rurack, Knut A1 - Resch-Genger, Ute A1 - Daub, J. T1 - Ultrafast charge transfer in amino-substituted boron dipyrromethene dyes and Its inhibition by cation complexation - a new design concept for highly sensitive fluorescent probes N2 - The photophysical behavior of a newly synthesized aza crown-substituted boron-dipyrromethene (BDP) dye and its dimethylamino analogue were investigated with steady-state and time-resolved fluorometry and compared to a reference compound. In solvents more polar than hexane, excitation of the dyes leads to a fast charge transfer from the locally excited (LE) state to a weakly emissive charge-transfer (CT) state. The donor-substituted compounds show dual emission from the LE and CT state, both fluorescence quantum yields being low. The rate constant of excited-state charge separation, calculated from the global analysis of time-resolved emission data, was determined to 1.6 × 1011 s-1 in 1,4-dioxane. The crowned compound forms 1:1-complexes with various alkali and alkaline-earth metal ions, which exist as two conformers in solution. In these complexes, coordination of the cation to the nitrogen donor atom of the crown inhibits the charge-transfer process, leading to a cation-dependent enhancement of the LE emission and the fluorescence lifetimes by factors >103. This efficient "switching on" of the fluorescence renders the crowned BDP dye an extremely sensitive fluorescent probe for metal ions. PY - 1998 DO - https://doi.org/10.1021/jp982701c SN - 1089-5639 SN - 1520-5215 VL - 102 IS - 50 SP - 10211 EP - 10220 PB - Soc. CY - Washington, DC AN - OPUS4-2095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rurack, Knut A1 - Kollmannsberger, M. A1 - Daub, J. T1 - A highly efficient sensor molecule emitting in the near infrared (NIR): 3,5-distyryl-8-(p-dimethylaminophenyl)-difluoroboradiaza-s-indacene N2 - The spectroscopic properties and the photophysical behaviour of difluoroboradiaza-s-indacene 1, especially designed for the near infrared (NIR) spectral region and equipped with a p-dimethylaminophenyl group at the meso-position, were studied by steady-state and time-resolved optical spectroscopy. Solvent-dependent measurements revealed that for 1, excited state deactivation is governed by population of a non-emissive charge transfer excited state (1CT) as the solvent polarity increases, whereas reference compound 2 shows strong fluorescence from a locally excited state (1LE) in all the solvents employed. Accordingly, protonation of 1 completely suppresses the quenching excited state charge transfer process and leads to strong enhancement of fluorescence in the NIR, distinguishing 1 as a very sensitive fluorescent sensor molecule for pH or solvent acidity in this favourable wavelength region. PY - 2001 DO - https://doi.org/10.1039/b007379m SN - 0398-9836 VL - 25 SP - 289 EP - 292 PB - Le Centre National de la Recherche Scientifique CY - Paris AN - OPUS4-1085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rurack, Knut A1 - Kollmannsberger, M. A1 - Daub, J. T1 - Molekulares Schalten im nahen Infrarot (NIR) mit einem funktionalisierten Bordipyrromethen-Farbstoff KW - Molekularer Schalter KW - Solvatochromie KW - Donor-Akzeptor-System KW - Elektrochromie PY - 2001 DO - https://doi.org/10.1002/1521-3757(20010119)113:2<396::AID-ANGE396>3.0.CO;2-W SN - 0044-8249 SN - 0932-2140 SN - 1521-3757 VL - 113 IS - 2 SP - 396 EP - 399 PB - Wiley-VCH CY - Weinheim AN - OPUS4-1077 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rurack, Knut A1 - Kollmannsberger, M. A1 - Daub, J. T1 - Molecular Switching in the Near Infrared (NIR) with a Functionalized Boron-Dipyrromethene Dye PY - 2001 DO - https://doi.org/10.1002/1521-3773(20010119)40:2<385::AID-ANIE385>3.0.CO;2-F SN - 1433-7851 SN - 1521-3773 SN - 0570-0833 VL - 40 IS - 2 SP - 385 EP - 387 PB - Wiley-VCH CY - Weinheim AN - OPUS4-1078 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -