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Monatshefte Für Chemie

Steffen Kurzhals, Michael Süss, Jelena Pejovic, Peter D J van Oostrum, Erik Reimhult, Ronald Zirbs
ABSTRACT: Crosslinked colloidal monolayers are promising as templates, lithographic masks, filtration membranes, or membranes for controlled release rates in drug delivery. We demonstrate assembly of monodisperse micron-sized polystyrene (PS) beads at an air/water interface, which are transformed into crystalline monolayers using addition of surface-active agents. Vapor annealing methods with solvents (toluene and xylene) and crosslinking agents (divinylbenzene) were investigated regarding their ability to crosslink these floating monolayers directly at the interface, generating crosslinked membranes with crystal size up to 44 cm(2), domain size up to 1...
2017: Monatshefte Für Chemie
Felix Biegger, Felix Jungwirth, Michael Stanislaus Seifner, Christoph Rameshan, Sven Barth
ABSTRACT: Thioether-functionalised indium aminoalcoholates have been used as single-source precursors in aerosol-assisted CVD processes. The obtained In2O3-x S x oxysulphide deposits show either a single indium sulphide phase for deposits with high sulphide content [>75% (S/(S + O)) for the t-butyl derivatives] or pronounced phase separation in indium oxide and indium sulphide for lower sulphide content [<62% (S/(S + O)) for the n-butyl derivatives]. In addition to thin films, polycrystalline 1D structures are obtained at slightly modified synthesis conditions...
2017: Monatshefte Für Chemie
Christine Artner, Ulrich Schubert
ABSTRACT: The carboxylate-substituted mixed-metal oxo clusters Pb6Ti6O9(acetate)(methacrylate)17 and Pb4Ti8O10(OiPr)18(acetate)2 contain a higher number of lead atoms in the cluster core than previously reported compounds. The metal atoms in both clusters are arranged in three layers of different composition, which are connected through oxygen, propionate and/or carboxylate bridges. GRAPHICAL ABSTRACT: HASH(0x47162b8)
2017: Monatshefte Für Chemie
Radomir Jasiński, Karolina Kula, Agnieszka Kącka, Barbara Mirosław
ABSTRACT: Reactions between (E)-2-aryl-1-cyano-1-nitroethenes and diazafluorene lead to acyclic 2,3-diazabuta-1,3-diene derivatives, instead of the expected pyrazoline systems. DFT calculations suggest that this is a consequence of formation of zwitterionic structure in the first stage of the reaction. It must be noted that this is a specific property of the (E)-2-aryl-1-cyano-1-nitroethenes group, in contrast to most other conjugated nitroalkenes. GRAPHICAL ABSTRACT: HASH(0x4195020) ...
2017: Monatshefte Für Chemie
Dominik Farka, H Coskun, P Bauer, D Roth, B Bruckner, Petr Klapetek, N Serdar Sariciftci, P Stadler
ABSTRACT: A stringent limitation in many optoelectronic devices, such as solar cells and light emitting diodes, is the intrinsic need for a transparent electrode. Uniting relevant aspects, indium tin oxide (ITO) is often the material of choice, however, alternatives are sought and being in particular found in conductive polymers. In this work, we present a novel doping strategy to arrive at highly conducting polymeric material based on poly-3,4-ethylenedioxythiophene (PEDOT). Based on commercial high conductivity PEDOT:PSS (Clevios PH 1000), and a post processing with aqueous triflic acid delivers a material that is both transparent and of low resistivity (5...
2017: Monatshefte Für Chemie
Astrid-Caroline Knall, Andrew O F Jones, Birgit Kunert, Roland Resel, David Reishofer, Peter W Zach, Mindaugas Kirkus, Iain McCulloch, Thomas Rath
ABSTRACT: Herein, we describe the synthesis and characterization of a conjugated donor-acceptor copolymer consisting of a pyrrolopyridazinedione (PPD) acceptor unit, and a benzodithiophene (BDT) donor unit. The polymerization was done via a Stille cross-coupling polycondensation. The resulting PPD-BDT copolymer revealed an optical bandgap of 1.8 eV and good processability from chlorobenzene solutions. In an organic solar cell in combination with PC70BM, the polymer led to a power conversion efficiency of 4...
2017: Monatshefte Für Chemie
Sebastian F Hoefler, Gregor Trimmel, Thomas Rath
ABSTRACT: Metal halide perovskites have revolutionized the field of solution-processable photovoltaics. Within just a few years, the power conversion efficiencies of perovskite-based solar cells have been improved significantly to over 20%, which makes them now already comparably efficient to silicon-based photovoltaics. This breakthrough in solution-based photovoltaics, however, has the drawback that these high efficiencies can only be obtained with lead-based perovskites and this will arguably be a substantial hurdle for various applications of perovskite-based photovoltaics and their acceptance in society, even though the amounts of lead in the solar cells are low...
2017: Monatshefte Für Chemie
Dariusz Guziejewski, Sylwia Smarzewska, Radovan Metelka, Agnieszka Nosal-Wiercińska, Witold Ciesielski
ABSTRACT: The use of square wave voltammetry (SWV) and square wave adsorptive stripping voltammetry (SWAdSV) in conjunction with a cyclic renewable silver amalgam film electrode for the determination of flumetralin is presented. Poor separation of two overlapped reduction peaks is significantly improved when hexadecyltrimethylammonium bromide is used as a component of the supporting electrolyte solution (together with BR buffer pH 9.5). The SW technique parameters were investigated and found optimal as follows: frequency 50 Hz, amplitude 40 mV, and step potential 5 mV...
2017: Monatshefte Für Chemie
Mariola Brycht, Agnieszka Nosal-Wiercińska, Karolina Sipa, Konrad Rudnicki, Sławomira Skrzypek
ABSTRACT: In this paper, the square-wave adsorptive stripping voltammetric (SWAdSV) determination of the veterinary drug closantel using a renewable silver amalgam film electrode (Hg(Ag)FE) is presented. As observed in SWAdSV, closantel provided one well-shaped reduction peak suitable for analytical purposes at potential ca. -1.4 V in the Britton-Robinson (B-R) buffer at pH 7.0. At optimal conditions, the SWAdSV response of Hg(Ag)FE for determining closantel was linear over two concentration ranges of 5...
2017: Monatshefte Für Chemie
Sergey Zakharov, Olga Nurieva, Katerina Kotikova, Jaromir Belacek, Tomas Navratil, Daniela Pelclova
ABSTRACT: Mass methanol poisonings present a serious problem for health systems worldwide, with poor outcome associated with delayed treatment. Positive pre-hospital serum ethanol concentration may have predictive value as the prognostic factor of the treatment outcome. We studied the effect of positive serum ethanol level on admission to hospital on survival in patients treated during the Czech methanol outbreak during 2012-2014. Cross-sectional cohort study was performed in 100 hospitalized patients with confirmed methanol poisoning...
2017: Monatshefte Für Chemie
Matthias Weil
ABSTRACT: The reversible phase transition of Pb8F14I2 is of continuous type and takes place at about 107 °C as monitored by temperature-dependent single crystal and powder X-ray diffraction measurements, optical microscopy, and differential scanning calorimetry. The low-temperature ferroelastic phase crystallizes in the orthorhombic crystal system (23 °C, Bmmb, Z = 2, a = 6.0699(6) Å, b = 6.0165(6) Å, c = 25.077(2) Å, 1487 structure factors, 41 parameter, R(F(2) ) = 0...
2017: Monatshefte Für Chemie
Roland W Bittner, Katharina Bica, Helmuth Hoffmann
ABSTRACT: Liquid-repellent surfaces based on slippery liquid-infused porous substrates (SLIPS) were prepared from porous, nanostructured silicon surfaces with different surface functionalization, infused with the polar ionic liquid 1-ethyl-3-methylimidazolium methylsulfate ([C2mim]MeSO4). Contrary to nonpolar SLIPS based on perfluorinated substrates and infusion liquids, [C2mim]MeSO4 forms stable SLIPS with high energy surfaces like native silicon (Si-SiO2) or ionic liquid-functionalized silicon (Si-[C3mim]Cl), whose liquid-repellent properties against low surface tension liquids (toluene, cyclohexane) were demonstrated by very low sliding angles (α < 3°) and low contact angle hysteresis (Δθ < 10°)...
2017: Monatshefte Für Chemie
Florian Rudroff, Michael J Fink, Ramana Pydi, Uwe T Bornscheuer, Marko D Mihovilovic
ABSTRACT: This study investigates the substrate profile of cycloalkanone monooxygenase and 2-oxo-Δ(3)-4,5,5-trimethylcyclopentenylacetyl-coenzyme A monooxygenase, two recently discovered enzymes of the Baeyer-Villiger monooxygenase family, used as whole-cell biocatalysts. Biooxidations of a diverse set of ketones were performed on analytical scale: desymmetrization of substituted prochiral cyclobutanones and cyclohexanones, regiodivergent oxidation of terpenones and bicyclic ketones, as well as kinetic resolution of racemic cycloketones...
2017: Monatshefte Für Chemie
Sandro Neuner, Christoph Kreutz, Ronald Micura
ABSTRACT: We have developed an efficient route for the synthesis of (15)N(7)-labeled adenosine as phosphoramidite building block for site- and atom-specific incorporation into RNA by automated solid-phase synthesis. Such labeled RNA is required for the evaluation of selected non-canonical base pair interactions in folded RNA using NMR spectroscopic methods. GRAPHICAL ABSTRACT: HASH(0x41a94a8)
2017: Monatshefte Für Chemie
Danny Müller, Christian Knoll, Peter Weinberger
ABSTRACT: N1-substituted tetrazoles are interesting ligands in transition metal coordination chemistry, especially in the field of spin crossover. Their synthesis is performed in most cases according to the Franke-synthesis, using a primary amine as reagent introducing the substitution pattern. To enhance flexibility in means of substrate scope, we developed a new protocol based on alkylation of lithium tetrazolate with alkyl bromides. The N1-N2 isomerism of the tetrazole during the alkylation was successfully suppressed by use of highly pure lithium tetrazolate and 30 vol...
2017: Monatshefte Für Chemie
Manuel Hollauf, Merima Cajlakovič, Martin Tscherner, Stefan Köstler, Astrid-Caroline Knall, Gregor Trimmel
ABSTRACT: Highly fluorescent and photostable (2-alkyl)-1H-benzo[de]isoquinoline-1,3(2H)-diones with a polymerizable norbornene scaffold have been synthesized and polymerized using ring-opening metathesis polymerization. The monomers presented herein could be polymerized in a living fashion, using different comonomers and different monomer ratios. All obtained materials showed good film-forming properties and bright fluorescence caused by the incorporated push-pull chromophores. Additionally, one of the monomers containing a methylpiperazine functionality showed protonation-dependent photoinduced electron transfer which opens up interesting applications for logic gates and sensing...
2017: Monatshefte Für Chemie
Martin Walter, Claudia Kohout, Markus Blaukopf, Paul Kosma
ABSTRACT: Phosphoethanolamine derivatives of the bacterial saccharide l-glycero-d-manno-heptose have been prepared using a phosphoramidite-based coupling reaction at position 4 of a side-chain-protected 2,3-O-orthoester methyl heptoside and at position 3 of a 3,4-diol heptoside, respectively. Global deprotection afforded the corresponding 2-aminoethylphosphodiester derivatives as substrates for crystallographic and binding studies with lectins and antibodies targeting the inner core structure of bacterial lipopolysaccharides...
2017: Monatshefte Für Chemie
Mathias Mastalir, Karl Kirchner
ABSTRACT: Kumada-Corriu and Negishi cross-coupling reactions, catalyzed efficiently by a Ni(II) PNP pincer complex containing a triazine backbone, are described. The catalyst is able to react with both activated and inactivated aryl halides including chlorides as well as phenol derivatives such as tosylates and mesylates to give the corresponding cross-coupling products in good to excellent isolated yields. A high diversity of substrates was tested under moderate conditions for both types of reactions...
2017: Monatshefte Für Chemie
Birgit Gröll, Patricia Schaaf, Michael Schnürch
ABSTRACT: Alkynylation reactions of N-protected tetrahydroisoquinolines have been performed using several different protocols of cross dehydrogenative coupling. Initially, a CuCl-catalyzed method was investigated, which worked well with three different N-protecting groups, namely phenyl, PMP, and benzyl and t-BuOOH as oxidant in acetonitrile as solvent. The peroxide could then be replaced by simple air and acetonitrile for water, leading to an overall very environmentally friendly protocol...
2017: Monatshefte Für Chemie
Petra Križková, Anna Wieczorek, Friedrich Hammerschmidt
ABSTRACT: 2-Deoxy-D-ribose was converted to α/β-mixtures of methyl 3-O-acetyl- and methyl 3-O-benzoyl-2-deoxy-5-(p-toluenesulfonyl)-D-ribofuranosides. These were reacted with boron trichloride to generate ribofuranosyl chlorides, which afforded precursors for tracers to image tumor hypoxia on substitution with salts of 2-nitroimidazole. The anomeric ratio of the nucleosides was delicately influenced by the reaction conditions. GRAPHICAL ABSTRACT: HASH(0x47107f0) ...
2017: Monatshefte Für Chemie
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