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91.
Budischowsky David Zwirchmayr Nele Sophie Hosoya Takashi Bacher Markus Hettegger Hubert Potthast Antje Rosenau Thomas 《Cellulose (London, England)》2021,28(10):6051-6071
Cellulose - Chromophores, colored substances of rather high stability that reduce brightness, are present in all kinds of cellulosic products, such as pulp, fibers, aged cellulosic material, and... 相似文献
92.
Loffhagen Detlef Becker Markus M. Czerny Andreas K. Klages Claus-Peter 《Plasma Chemistry and Plasma Processing》2021,41(1):289-334
Plasma Chemistry and Plasma Processing - A time-dependent, spatially one-dimensional fluid-Poisson model is applied to analyze the impact of small amounts of tetramethylsilane (TMS) as precursor on... 相似文献
93.
Markus Bursch Lukas Kunze Dr. Amol M. Vibhute Dr. Andreas Hansen Prof. Dr. Kana M. Sureshan Dr. Peter G. Jones Prof. Dr. Stefan Grimme Prof. Dr. Daniel B. Werz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(14):4627-4639
The noncovalent interactions between azides and oxygen-containing moieties are investigated through a computational study based on experimental findings. The targeted synthesis of organic compounds with close intramolecular azide–oxygen contacts yielded six new representatives, for which X-ray structures were determined. Two of those compounds were investigated with respect to their potential conformations in the gas phase and a possible significantly shorter azide–oxygen contact. Furthermore, a set of 44 high-quality, gas-phase computational model systems with intermolecular azide–pnictogen (N, P, As, Sb), –chalcogen (O, S, Se, Te), and –halogen (F, Cl, Br, I) contacts are compiled and investigated through semiempirical quantum mechanical methods, density functional approximations, and wave function theory. A local energy decomposition (LED) analysis is applied to study the nature of the noncovalent interaction. The special role of electrostatic and London dispersion interactions is discussed in detail. London dispersion is identified as a dominant factor of the azide–donor interaction with mean London dispersion energy-interaction energy ratios of 1.3. Electrostatic contributions enhance the azide–donor coordination motif. The association energies range from −1.00 to −5.5 kcal mol−1. 相似文献
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Markus Follmann Nils Griebenow Michael G. Hahn Ingo Hartung Franz‐Josef Mais Joachim Mittendorf Martina Schfer Hartmut Schirok Johannes‐Peter Stasch Friederike Stoll Alexander Straub Peter Jeschke Ralf Nauen Michael Edmund Beck Hans‐Wilhelm Engels Hans‐Georg Pirkl Reinhard Albers Rolf W. Albach Jens Krause Andreas Hoffmann Holger Casselmann Jeff Dormish 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2013,125(36):9503-9503
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An alternative pathway for the biosynthesis of the fungal alkaloid necatorone has been studied using fluorine-labeled 3-(2-carboxyphenylamino)-l-tyrosine. Although no incorporation of this compound could be detected in feeding experiments with young specimens of Lactarius necator, an analogous 3-aminotyrosine derivative could be converted synthetically into the oxopyridoacridine core structure of necatorone. In experiments aimed at the synthesis of aaptamine-type alkaloids, an unprecedented cyclization of a 3-aminotyrosine-methyl propiolate adduct to a methyl isoquinoline-3-carboxylate was observed. A mechanism is proposed, in which C3 of the propiolate delivers C1 of the isoquinoline nucleus. 相似文献
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Abstract The following analytical method has been used to identify some odorous compounds in the air of the water treatment plant Werdholzli, Zurich: sampling of contaminated air with the help of activated carbon, desorption by the solvents carbon disulphide and methylene chloride, separation of the carbon disulfide extract into a polar and a nonpolar fraction by adsorption column chromatography on silica. Hereafter gaschromatographic analysis of the polar fraction on glass capillary column (Ucon HB 5100); detection and identification were achieved by flame ionisation, thermoionic nitrogen selective detector and computerized mass spectrometry (Finnigan 3200 F, data system 6110). The results show the presence of sulfur compounds: thiophenes, thiazoles; nitrogen compounds: pyrazines; oxygen compounds: phenols, alcohols and some unsatured hydrocarbons. The malodorous compounds were sulfur and nitrogen compounds in the range of 0.01-0.1 ppm. 相似文献