TY - JOUR A1 - Rudert, R. A1 - Schulz, Burkhard A1 - Reck, Günter A1 - Vollhardt, D. A1 - Kriwanek, J. T1 - (Carboxymethyl)dimethylundecylammonium bromide N2 - The title compound, C₁₅H₃₂NO₂⁺.Br⁻, crystallizes to form layers with interdigitating hydrocarbon chains stabilized by Br⁻۰۰۰H—O hydrogen bonds and Br⁻۰۰۰N⁺ contacts. KW - (Carboxymethyl)dimethylundecylammonium bromide KW - Crystal structure PY - 1995 DO - https://doi.org/10.1107/s0108270194011443 SN - 0108-2701 VL - 51 SP - 768 EP - 770 PB - Wiley-Blackwell CY - Oxford AN - OPUS4-56998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hennig, C. A1 - Reck, Günter A1 - Reich, T. A1 - Roßberg, A. A1 - Kraus, Werner A1 - Sieler, J. T1 - EXAFS and XRD investigations of zeunerite and meta-zeunerite N2 - In this paper EXAFS was used to determine bond lengths in the structures of zeunerite and meta-zeunerite. The atomic distances between heavy and light scatterers observed using EXAFS in meta-zeunerite deviate approximately 0.1 Å from literature data of single-crystal X-ray diffraction measurements. Because this difference is significant higher than the error limits of EXAFS measurements, the complete crystal structure of meta-zeunerite, Cu[UO2AsO4]2·8 H2O, is revised by X-ray structure analysis. The bond length determinations by EXAFS and the revised XRD data agree within the experimental error limits. In this study EXAFS spectroscopy has proven to be an useful tool for determining precise local bond lengths in the environment of heavy atoms. Moreover, the crystal structure of zeunerite, Cu[UO2AsO4]2·12 H2O, hitherto not been described in the literature, was investigated. Reflex broadening effects and intergrowth relationship between zeunerite and meta-zeunerite show that meta-zeunerite grows in nature due to dehydration of zeunerite. The structural transition from zeunerite to meta-zeunerite is connected with a change in the uranyl arsenate layer arrangement and the crystal water content. PY - 2003 DO - https://doi.org/10.1524/zkri.218.1.37.20776 SN - 0044-2968 VL - 218 IS - 1 SP - 37 EP - 45 PB - Oldenbourg CY - München AN - OPUS4-2291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rurack, Knut A1 - Bricks, J. L. A1 - Reck, Günter A1 - Schulz, Burkhard A1 - Spieles, Monika T1 - Cation coordination of bisamidopyridine-derived receptors as investigated in the solid-state and in solution N2 - A bisamidopyridine-type receptor, N,N'-bis(6-methyl-2-pyridyl)pyridine-2,6-dicarboxamide (1), and its CoIII complex were prepared and their X-ray structures were compared to those of N,N'-diphenylpyridine-2,6-dicarboxamide (2) and CoIII(2)2. Introduction of the two additional coordinative groups resulted in second-order interactions between the central ion and the nitrogen atoms of the terminal pyridine moieties in the crystalline state. Solution studies in acetonitrile revealed the importance of these interactions for the ligand's metal ion recognition ability. Whereas 2 only binds to PbII and CuII, 1 yields complexes with a majority of the heavy and transition metal ions studied, CoII, NiII, CuII, ZnII, FeIII, FeII, HgII, and PbII, respectively. The cation binding properties in solution were investigated by absorption spectroscopy and in the case of 1-MII/III, the formation of two spectroscopically distinguishable types of complexes was found. Protonation experiments and theoretical considerations helped to gain further insight into possible modes of coordination in solution. KW - Pyridine carboxamides KW - Ion recognition KW - Crystal structure KW - N-coordination PY - 2003 DO - https://doi.org/10.1080/1061027031000078239 SN - 1061-0278 SN - 1029-0478 VL - 15 IS - 3 SP - 189 EP - 197 PB - Gordon and Breach Science Publ. CY - New York, NY AN - OPUS4-2106 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - Rurack, Knut A1 - Schulz, Burkhard A1 - Reck, Günter A1 - Resch-Genger, Ute A1 - Bricks, J. A1 - Maus, M. T1 - Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Delta2-pyrazolines - Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties N2 - The spectroscopic properties of 1-phenyl-3-benzothiazol-2-yl-5-(4-R-phenyl)-2-pyrazolines are strongly dependent on both the electronic nature of the substituent R and solvent polarity. As revealed by spectroscopic studies as a function of solvent polarity as well as temperature, for electron-rich amino donor substituents in polar solvents, deactivation of the strongly emissive charge transfer (CT) state of the basic 1-phenyl-3-benzothiazol-2-yl-2-pyrazoline chromophore has to compete with a fast intramolecular electron transfer (ET) quenching reaction. In the case of the dimethylamino derivative (R = DMA), the rate constant of ET in acetonitrile was determined to ket = 3 × 1010 s-1. This ET process can be utilized for metal ion sensing by introducing nitrogen containing aza crown ether receptor units to the 4-position of the 5-phenyl group. The spectroscopically determined ET rates of the 5-(N-alkyl)anilino substituents, a DMA, a tetrathia- (AT415C5), and a tetraoxa-monoaza-15-crown-5 (A15C5) group, correlate with electrochemical data and increase in the order AT415C5 < A15C5 < DMA. The metal ion sensing abilities of the two crowned derivatives are presented, and the different signaling mechanisms include binding to the crown ether in the 4-R-position, chelate formation in the 3-benzothiazol-2-yl-2-pyrazoline moiety, and electrophotochemical detection. Furthermore, the rigid "pseudo spiro" geometry of the molecules, which holds the three substituents of the central 2-pyrazoline ring in a fixed prearrangement, was confirmed by X-ray structure analysis. KW - Farbstoff KW - Fluoreszenz KW - Kationen KW - Photophysik PY - 2000 DO - https://doi.org/10.1021/jp993404q SN - 1089-5639 SN - 1520-5215 VL - 104 IS - 26 SP - 6171 EP - 6188 PB - Soc. CY - Washington, DC AN - OPUS4-841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rurack, Knut A1 - Bricks, J. L. A1 - Reck, Günter A1 - Radeglia, Reiner A1 - Resch-Genger, Ute T1 - Chalcone-analogue dyes emitting in the near-infrared (NIR) - influence of donor-acceptor substitution and cation complexation on their spectroscopic properties and X-ray structure N2 - The photophysical properties of several newly synthesized 1-benzothiazole-3-(4-donor)-phenyl-substituted prop-2-en-1-ones (substituted chalcones) are studied as a function of solvent polarity, temperature, and metal ion by employing steady-state and time-resolved spectroscopy. To investigate the effect of bulkiness and donor strength of the anilino moiety on the spectroscopic properties of these dyes, the spectroscopic behavior of the 4-N-dimethylamino (DMA), the 4-N-tetraoxa-monoaza-15-crown-5 (A15C5), and the 4-N-tetrathia-monoaza-15-crown-5 (AT415C5) derivatives as well as the 3-julolidino (Jul) analogue is compared. Absorption and fluorescence measurements reveal that the strength of the intramolecular charge transfer (ICT) process increases on the order of AT415C5 < A15C5 ~ DMA < Jul. The slight but significant differences between the two crowned dyes are well-supported by the results of the X-ray structure analysis, where oxa aza and thia aza crowns show essentially different geometries. For both fluoroionophores, this variation of heteroatom substitution pattern of the receptor induces specific cation selectivities. The spectroscopic effects accompanying complexation and the different binding sites are studied by steady-state and time-resolved optical spectroscopy as well as NMR spectroscopy. Whereas the probe carrying a tetraoxa monoaza 15-crown-5 receptor shows cation-induced fluorescence enhancement in the presence of alkali and alkaline-earth metal ions, its tetrathia analogue binds selectively to HgII, AgI, and CuII in acetonitrile. Moreover, an increase in fluorescence is observed for the latter probe even upon coordination to the widely known fluorescence quencher HgII. Besides receptor complexation, chelate formation in the benzothiazole-carbonyl acceptor part of these intrinsic fluorescent probes is possible, leading to a chromoionophoric signaling behavior in the near-infrared (NIR). PY - 2000 DO - https://doi.org/10.1021/jp994269k SN - 1089-5639 SN - 1520-5215 VL - 104 IS - 14 SP - 3087 EP - 3109 PB - Soc. CY - Washington, DC AN - OPUS4-2088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meißner, T. A1 - Bergmann, R. A1 - Oswald, J. A1 - Rode, K. A1 - Stephan, H. A1 - Richter, W. A1 - Zänker, H. A1 - Kraus, Werner A1 - Emmerling, Franziska A1 - Reck, Günter T1 - Chitosan-encapsulated Keggin anion [Ti2W10PO40]7-.Synthesis, characterization and cellular uptake studies N2 - The Keggin type polyoxotungstate [Ti2W10PO40]7- forms stable associates with the biopolymer chitosan in the nanometer size range. The cluster compound crystallizes from aqueous solution as K4H3[Ti2W10PO40] · 15H2O having a tetragonal structure. Both, the cluster compound and the chitosan/[Ti2W10PO40] associates show a high hydrolytic stability at pH 7.4. The associates formed between the cluster anion [Ti2W10PO40]7- with the polyaminosaccharide chitosan have been characterized by photon correlation spectroscopy, scanning electron microscopy, filtration, centrifugation and zeta potential measurements. The size of the associates formed is in the range of ca. 5×101 to 5×102 nm. These particles have a defined stoichiometry with 5–6 cluster anions bound per molecule chitosan. The isoelectric point determined by zeta potential measurements was found for a cluster anion to chitosan molar ratio of 5.5, indicating the charge neutralization between protonated chitosan and [Ti2W10PO40]7- anions. Cellular uptake studies with [Ti2W10PO40]7- using tumor cell lines FaDu (human squamous carcinoma) and HT-29 (human adenocarcinoma) showed that the tungsten amount inside the cells is remarkably enhanced in the presence of chitosan. KW - Cluster compound KW - Keggin structure KW - Bipolymer KW - Chitosan PY - 2006 DO - https://doi.org/10.1007/s11243-006-0035-z SN - 0340-4285 SN - 1572-901X VL - 31 IS - 5 SP - 603 EP - 610 PB - Springer CY - Dordrecht AN - OPUS4-12568 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 - Schiller, E. A1 - Kraus, Werner A1 - Reck, Günter A1 - Spies, H. A1 - Pietzsch, H.-J. T1 - [2-Carboxy-2,2',2''-nitrilotris(ethanethiolato)-kappa4N,S,S',S''](triphenyl-phosphine-kappaP)rhenium(III) acetone solvate N2 - The title compound, [Re(C7H12NO2S3)(C18H15P)]·C3H6O, crystallizes from a solution in chloro­form–acetone–cyclo­­hexane with enantiomers disordered equally over each mol­ecular site. Hydrogen bonds between the carbox­yl groups form dimers in the crystal structure. PY - 2005 DO - https://doi.org/10.1107/S1600536805018660 SN - 1600-5368 VL - 61 IS - 7 SP - m1373 EP - m1375 PB - Munksgaard CY - Copenhagen AN - OPUS4-7613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - López, J.P. A1 - Kraus, Werner A1 - Reck, Günter A1 - Thünemann, Andreas A1 - Kurth, D.G. T1 - Alternating perpendicular 1-D channels in the supramolecular structure of the copper(II) complex [Cu(pyterpy)2](PF6)2 . CH3OH . 0.5 CH2Cl2 (pyterpy = 4'-(4'''-pyridyl)-2,2':6',2''-terpyridine) KW - 4´-(4´´´-pyridyl)-2,2´:6´2´´-terpyridine KW - Copper complexes KW - Crystal structure KW - Supramolecular chemistry KW - Pi-pi stacking PY - 2005 SN - 1387-7003 VL - 8 SP - 281 EP - 284 PB - Elsevier CY - Amsterdam AN - OPUS4-6301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -