TY - JOUR A1 - Reck, Günter A1 - Schulz, Burkhard A1 - Bricks, J. A1 - Li, Yanqin A1 - Resch-Genger, Ute T1 - Monoalkylated 4'-aryl-substituted terpyridines N2 - 1-Methyl-2-[4-phenyl-6-(pyridinium-2-yl)­pyridin-2-yl]­pyridinium diperchlorate, C22H19N32+·2ClO4-, (I), and 2-[4-(methoxy­phenyl)-2,2'-bipyridin-6-yl]-1-methyl­pyridinium iodide, C23H20N3O+·I-, (II), both crystallize in the monoclinic space group P21/c. In contrast with the monocharged mol­ecule of (II), the doubly charged mol­ecule of (I) contains an additional protonated pyridine ring. One of the two perchlorate counter-anions of (I) interacts with the cation of (I) via an N—HO hydrogen bond. In (II), two mol­ecules related by a centre of symmetry are connected by weak ?–? interactions, forming dimers in the crystal structure. KW - X-ray structure analysis KW - Fluorescent sensors KW - Molecular conformation KW - Intermolecular interactions PY - 2004 DO - https://doi.org/10.1107/S010827010400825X SN - 0108-2701 SN - 1600-5759 VL - 60 SP - o402 EP - o404 PB - Blackwell Publ. CY - Oxford AN - OPUS4-3563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Bricks, J. L. A1 - Resch-Genger, Ute A1 - Kraus, Werner A1 - Schulz, Burkhard A1 - Li, Yanqin A1 - Reck, Günter T1 - Influence of the donor substituent and acceptor alkylation on the structure-analytical properties of mono- and bifunctional biphenyl-type fluorescent reporters N2 - A systematic structural investigation of R-phenyl-substituted 2,2':6',2"-terpyridines, a family of mono- and bifunctional charge transfer (CT)-operated fluorescent reporters for protons and metal ions, is presented. These molecules are equipped with non-binding and analyte coordinating donor substituents R (R = CF3, H, OMe, OH, DMA, A15C5 equaling monoaza-15-crown-5) of various donor strength and display CT-controlled spectroscopic properties and communication of analyte–receptor interactions. The crystal structures of the neutral fluorescent probes are compared to the structures of their terpyridine-alkylated or -protonated counterparts that represent model systems for acceptor protonation or cation coordination. The aim is here a better understanding of the complexation-induced structural and spectroscopic changes and the identification of common packing motifs of bpb-R thereby taking into account the importance of terpyridine building blocks for the construction of supramolecular systems and coordination arrays revealing π–π interactions. KW - Biphenyl KW - Terpyridine KW - Crystal structure KW - Fluorescent probe KW - Charge transfer KW - Bifunctional PY - 2008 DO - https://doi.org/10.1016/j.molstruc.2007.03.025 SN - 0022-2860 SN - 1872-8014 SN - 0377-046X VL - 874 IS - 1-3 SP - 14 EP - 27 PB - Elsevier CY - Amsterdam AN - OPUS4-17087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Li, Yanqin A1 - Bricks, J. L. A1 - Resch-Genger, Ute A1 - Spieles, Monika A1 - Rettig, W. T1 - Bifunctional Charge Transfer Operated Fluorescent Probes with Acceptor and Donor Receptors. 2. Bifunctional Cation Coordination Behavior of Biphenyl-Type Sensor Molecules Incorporating 2,2':6',2''-Terpyridine Acceptors N2 - Based on donor (D)-acceptor (A) biphenyl (b) type molecules, a family of fluorescent reporters with integrated acceptor receptors and noncoordinating and coordinating donor substituents of varying strength has been designed for ratiometric emission sensing and multimodal signaling of metal ions and protons. In part 2 of this series on such charge transfer (CT) operated mono- and bifunctional fluorescent devices, the cation coordination behavior of the sensor molecules bpb-R equipped with a proton- and cation-responsive 2,2':6',2' '-terpyridine (bp) acceptor and either amino-type donor receptors (R = DMA, A15C5 = monoaza-15-crown-5) or nonbinding substituents (R = CF3, H, OMe) is investigated employing the representative metal ions Na(I), Ca(II), Zn(II), Hg(II), and Cu(II) and steady-state and time-resolved fluorometry. The bpb-R molecules, the spectroscopic behavior and protonation behavior of which have been detailed in part 1 of this series, present rare examples for CT-operated bifunctional fluorescent probes that can undergo consecutive and/or simultaneous analyte recognition. The analyte-mediated change of the probes' intramolecular CT processes yields complexation site- and analyte-specific outputs, i.e., absorption and fluorescence modulations in energy, intensity, and lifetime. As revealed by the photophysical studies of the cation complexes of these fluoroionophores and the comparison to other neutral and charged D-A biphenyls, the spectroscopic properties of the acceptor chelates of bpb-R and A- and D-coordinated bpb-R are governed by CT control of an excited-state barrier toward formation of a forbidden charge transfer state, by the switching between analytically favorable anti-energy and common energy gap law type behavior, and by the electronic nature of the ligated metal ion. This accounts for the astonishingly high fluorescence quantum yields of the acceptor chelates of bpb-R equipped with weak or medium-sized donors and the red emission of D- and A-coordinated bpb-R observed for nonquenching metal ions. PY - 2006 DO - https://doi.org/10.1021/jp062013q SN - 1089-5639 SN - 1520-5215 VL - 110 IS - 38 SP - 10972 EP - 10984 PB - Soc. CY - Washington, DC AN - OPUS4-14207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Li, Yanqin A1 - Bricks, J. L. A1 - Kharlanov, V. A1 - Rettig, W. T1 - Bifunctional Charge Transfer Operated Fluorescent Probes with Acceptor and Donor Receptors - 1. Biphenyl-Type Sensor Molecules with Protonation-Induced Anti-Energy Gap Rule Behavior N2 - On the basis of biphenyl (b) type molecules bpb-R substituted with a 2,2':6',2' '-terpyridine acceptor (bp) and either amino-type donor receptors (R = dimethylamino (DMA), A15C5 = monoaza-15-crown-5) or nonbinding substituents (R = CF3, H, OMe) of various donor strengths, we developed a family of charge transfer (CT) operated monofunctional and bifunctional fluorescent sensors for protons and metal ions. These molecules are designed to communicate the interaction of an analyte with the acceptor and the donor receptor differing in basicity and cation selectivity by clearly distinguishable spectral shifts and intensity modulations in absorption and in emission as well as in fluorescence lifetime. From the dependence of the fluorescence spectra, fluorescence quantum yields, and fluorescence lifetimes of bpb-R on solvent polarity and proton concentration, the photophysics of bpb-R and their protonated analogues can be shown to be governed by the relaxation to a CT state of forbidden nature and by the switching between anti-energy and energy gap law type behaviors. This provides the basis for analytically favorable red shifted emission spectra in combination with comparatively high fluorescence quantum yields. Accordingly, bpb-H and bpb-OMe are capable of ratiometric emission signaling of protons. bpb-DMA reveals a protonation-induced ON-OFF-ON switching of its emission. PY - 2006 DO - https://doi.org/10.1021/jp062010d SN - 1089-5639 SN - 1520-5215 VL - 110 IS - 38 SP - 10956 EP - 10971 PB - Soc. CY - Washington, DC AN - OPUS4-14208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Li, Yanqin A1 - Bricks, J.L. A1 - Resch-Genger, Ute A1 - Spieles, Monika A1 - Rettig, W. T1 - CT-Operated Bifunctional Fluorescent Probe Based on a Pretwisted Donor-Donor-Biphenyl N2 - Taking into account the structural requirements for TICT-type sensor molecules, a general synthetic route to derive pH and cation-responsive pretwisted donor (D)–donor (D) biphenyls (b) equipped with donor receptors is developed and a first model compound containing a mono aza-15-crown-5 and a DMA receptor is synthesized, see Scheme 1. The spectroscopic properties of this new bifunctional D–D biphenyl are studied in the non-polar and polar solvents cyclohexane, acetonitrile, and methanol. Protonation as well as complexation studies are performed with the representative metal ions Na(I), K(I), Ca(II), Ag(I), Zn(II), Cd(II), Hg(II), and Pb(II) to reveal the potential of this molecule for communication of whether none, only one, or both binding sites are engaged in analyte coordination by spectroscopically distinguishable outputs. The results are compared to those obtained with closely related donor (D)–acceptor (A) substituted biphenyl-type sensor molecules and are discussed within the framework of neutral and ionic D – A biphenyls. KW - Fluorescent probe KW - Biphenyl KW - TICT KW - Photophysics KW - Bifunctional PY - 2006 SN - 1053-0509 SN - 1573-4994 VL - 16 IS - 3 SP - 337 EP - 348 PB - Plenum Publ. Corp. CY - New York, NY AN - OPUS4-14198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -