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排序方式: 共有912条查询结果,搜索用时 31 毫秒
51.
Dr. Morten Gotthold Vinum Laura Voigt Colby Bell Dmytro Mihrin Prof. Dr. René Wugt Larsen Prof. Dr. Kensha Marie Clark Prof. Dr. Kasper S. Pedersen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(10):2143-2147
β-Diketonates, such as acetylacetonate, are amongst the most common bidentate ligands towards elements across the entire periodic table and are considered wholly redox-inactive in their complexes. Herein we show that complexation of 1,1,1,5,5,5-hexafluoroacetylacetonate (hfac−) to CrII spontaneously affords CrIII and a reduced β-diketonate radical ligand scaffold, as evidenced by crystallographic analysis, magnetic measurements, optical spectroscopy, reactivity studies, and DFT calculations. The possibility of harnessing β-diketonates as electron reservoirs opens up possibilities for new metal–ligand concerted reactivity in the ubiquitous β-diketonate coordination chemistry. 相似文献
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Sten Scheibye Bjarne S. Pedersen S.-O. Lawesson 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2):271-272
Abstract Recent studies have shown that the dimer of p-methoxyphenylthionophosphinesulfide, 1, is a very superior thiation reagent, as ketones, amides, and esters are in most cases quantitatively converted to their thio-analogues. 相似文献
54.
The synthesis of 4‐isothiocyanatomethyl‐pyridine 4 in 36% yield by Hasegawa and Kotani (Japanese patent 49088878, 1974) has spurred us to investigate this preparation in detail. In addition to this compound, 4‐isothiocyanatomethylene‐4H‐pyridine‐1‐carboxylic acid ethyl ester 3 can be isolated. The synthesis of both compounds 3 and 4 were optimized to 75% and 50% yield respectively. Reaction of compound 3 with methylamine gave thiourea derivatives 5, the same product obtained on reacting 4‐isothiocyanatomethyl‐pyridine 4 with methylamine. We succeed in adjusting the reaction conditions to obtain high yield either from compound 3 or isothiocyanate derivatives 4. 相似文献
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Eva Greibe Magnus Leth-Møller Sofie Stampe Per Ovesen Michael Pedersen Elke Hoffmann-Lücke 《Biomedical chromatography : BMC》2022,36(6):e5350
Artificial sweeteners are widely used as substitutes for sugar. The sweeteners are generally considered safe, however their whereabouts during pregnancy and lactation and the effect on child development are poorly explored. There is a need for new tools to measure these substances during pregnancy and lactation. Here, we describe the development and validation of a sensitive liquid chromatography–tandem mass spectrometry method for the simultaneous quantification of acesulfame, cyclamate, saccharin and sucralose in human plasma, umbilical cord blood, amniotic fluid and breast milk. The samples were prepared by protein precipitation and separated on a Luna Omega Polar C18 column (2.1 × 50 mm, 1.6 μm). Electrospray ionization in negative mode and multiple reaction monitoring were used to monitor the ion transitions. The validated concentration ranges were from 1 to 500 ng/ml (10–500 ng/ml for sucralose). Interassay precisions were all ≤15% and the accuracies were within ±15%. Stability, linearity, dilution integrity, carryover and recovery were also examined and satisfied the validation criteria. Finally, this analytical method was successfully applied on spiked samples of plasma, umbilical cord blood, amniotic fluid and breast milk, proving its suitability for use in clinical studies on artificial sweeteners, including during pregnancy and lactation. 相似文献
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Inside Cover: Fluoride‐Bridged {GdIII3MIII2} (M=Cr,Fe, Ga) Molecular Magnetic Refrigerants (Angew. Chem. Int. Ed. 9/2014)
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59.
P. S. Ramanujam Christian Holme Sren Hvilsted Marianne Pedersen Fulvio Andruzzi Massimo Paci Eliana L. Tassi Pierluigi Magagnini Uwe Hoffman Ingo Zebger Heinz W. Siesler 《先进技术聚合物》1996,7(9):768-776
Azobenzene side-chain liquid crystalline polyester structures suitable for permanent optical storage are described. The synthesis and characterization of the polyesters together with differential scanning calorimetry and X-ray investigations are discussed. Optical anisotropic investigations and holographic storage in one particular polyester are described in detail and polarized Fourier transform infrared spectroscopic data complementing the optical data are presented. Optical and atomic force microscope investigations point to a laser-induced aggregation as responsible for permanent optical storage. 相似文献
60.
In the development of therapeutic proteins, analytical assessment of structural stability and integrity constitutes an important activity, as protein stability and integrity influence drug efficacy, and ultimately patient safety. Existing analytical methodologies solely rely on relative changes in optical properties such as fluorescence or scattering upon thermal or chemical perturbation. Here, we present an absolute analytical method for assessing protein stability, structure, and unfolding utilizing Taylor dispersion analysis (TDA) and LED-UV fluorescence detection. The developed TDA method measures the change in size (hydrodynamic radius) and intrinsic fluorescence of a protein during in-line denaturation with guanidinium hydrochloride (GuHCl). The conformational stability of the therapeutic antibody adalimumab and human serum albumin were characterized as a function of pH. The simple workflow and low sample consumption (40 ng protein per data point) of the methodology make it ideal for assessing protein characteristics related to stability in early drug development or when having a scarce amount of sample available. 相似文献