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71.
The preparation of luminescent hydrogels based on the electrostatic self-assembly of 1-pyrenesulfonate (PyS) anions in a positively charged N-isopropylacrylamide (NiPAAm)/surfmer copolymer gel is described. The hydrogels were prepared from a micellar aqueous solution of 11-acryloyloxyundecyltrimethylammonium bromide and NiPAAm upon 60Co-gamma irradiation. For assembly of PyS, the gel was shrunken at 50 °C and re-swollen at 20 °C in an aqueous solution of sodium 1-pyrenesulfonate. Re-swelling was accompanied by electrostatic assembly of PyS anions within the gel. Subsequently, the excess non-bound PyS ions were removed by repeatedly swelling and shrinking the gel in pure water at 20 °C and 50 °C, respectively. Incorporation of PyS ions in the hydrogel was studied using UV/Vis spectroscopy and energy dispersive x-ray (EDX) measurements. The amount of electrostatically adsorbed PyS was found to be proportional to the amount of copolymerized surfmer. EDX studies indicated that 20% of the bromide counterions were replaced for PyS. The PyS counterions could be released again if the functionalized hydrogel was immersed in acidified water. At a pH of 1, an almost complete release of PyS was found after 250 h. The preparation method can be used to introduce a variety of functional properties in thermoresponsive charged copolymer gels. 相似文献
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O. Wo R. E. Liesegang H. Menzel Friedrich Müller Haurowitz P. Krais 《Colloid and polymer science》1931,55(3):360-365
Ohne Zusammenfassung 相似文献
75.
Friedrich Recht und Richard Reissner 《Fresenius' Journal of Analytical Chemistry》1935,103(7-8):261-269
Zusammenfassung Versuche, das wismutjodwasserstoffsaure 8-Oxychinolin zu einer brauchbaren gravimetrischen Bestimmungsmethode des Wismuts heranzuziehen, führten zu keinem Ergebnis. Hingegen lieferte die gravimetrische Wismutbestimmung mit Oxinacetat in essigsaurer Lösung nach gewissen, Abänderungen der ursprünglichen Bergschen Vorschrift sowohl makro- als auch mikroanalytisch völlig befriedigende Resultate. 相似文献
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Elisabeth Siebert Marius Horch Yvonne Rippers Johannes Fritsch Stefan Frielingsdorf Oliver Lenz Francisco VelazquezEscobar Friedrich Siebert Lars Paasche Uwe Kuhlmann Friedhelm Lendzian Maria‐Andrea Mroginski Ingo Zebger Peter Hildebrandt 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2013,125(19):5267-5270
78.
Multidimensional nano-HPLC coupled with tandem mass spectrometry for analyzing biotinylated proteins
Jens Sproß Sebastian Brauch Friedrich Mandel Moritz Wagner Stephan Buckenmaier Bernhard Westermann Andrea Sinz 《Analytical and bioanalytical chemistry》2013,405(7):2163-2173
Multidimensional high-performance liquid chromatography (HPLC) is a key method in shotgun proteomics approaches for analyzing highly complex protein mixtures by complementary chromatographic separation principles. Here, we describe an integrated 3D-nano-HPLC/nano-electrospray ionization quadrupole time-of-flight mass spectrometry system that allows an enzymatic digestion of proteins followed by an enrichment and subsequent separation of the created peptide mixtures. The online 3D-nano-HPLC system is composed of a monolithic trypsin reactor in the first dimension, a monolithic affinity column with immobilized monomeric avidin in the second dimension, and a reversed phase C18 HPLC-Chip in the third dimension that is coupled to a nano-ESI-Q-TOF mass spectrometer. The 3D-LC/MS setup is exemplified for the identification of biotinylated proteins from a simple protein mixture. Additionally, we describe an online 2D-nano-HPLC/nano-ESI-LTQ-Orbitrap-MS/MS setup for the enrichment, separation, and identification of cross-linked, biotinylated species from chemical cross-linking of cytochrome c and a calmodulin/peptide complex using a novel trifunctional cross-linker with two amine-reactive groups and a biotin label. Figure
Schematic representations of the online 3D-nano-HPLC/nano-ESI-Q-TOF-MS/MS setup; LP loading pump, NP nano-pump 相似文献
79.
Thomas Wiesner Dr. Zhu Wu Dr. Jie Han Prof. Dr. Lei Ji Dr. Alexandra Friedrich Dr. Ivo Krummenacher Michael Moos Prof. Dr. Christoph Lambert Prof. Dr. Holger Braunschweig Benjamin Rudin Dr. Hilmar Reiss Olena Tverskoy Dr. Frank Rominger Prof. Dr. Andreas Dreuw Prof. Dr. Todd B. Marder Dr. Jan Freudenberg Prof. Dr. Uwe H. F. Bunz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(69):e202201919
Tetraiodotetraazapentacene I4TAP , the last missing derivative in the series of halogenated silylated tetraazapentacenes, was synthesized via condensation chemistry from a TIPS-ethynylated diaminobenzothiadiazol in three steps. Single and double reduction furnished its air-stable monoanion and relatively air-stable dianion, both of which were characterized by crystallography. All three species are structurally and spectroscopically compared to non-halogenated TAP and Br4TAP . I4TAP is an n-channel material in thin-film transistors with average electron mobilities exceeding 1 cm2 (Vs)−1. 相似文献
80.
Jinxiong Lin Dr. Friedrich Wossidlo. Dr. Nathan T. Coles Manuela Weber Dr. Simon Steinhauer Priv.-Doz. Dr. Tobias Böttcher Prof. Dr. Christian Müller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(7):e202104135
A phosphinine-borane adduct of a Me3Si-functionalized phosphinine and the Lewis acid B(C6F5)3 has been synthesized and characterized crystallographically for the first time. The reaction strongly depends on the nature of the substituents in the α-position of the phosphorus heterocycle. In contrast, the reaction of B2H6 with various substituted phosphinines leads to an equilibrium between the starting materials and the phosphinine–borane adducts that is determined by the Lewis basicity of the phosphinine. The novel phosphinine borane adduct ( 6 -B(C6F5)3) shows rapid and facile insertion and [4+2] cycloaddition reactivity towards phenylacetylene. A hitherto unknown dihydro-1-phosphabarrelene is formed with styrene. The reaction with an ester provides a new, facile and selective route to 1-R-phosphininium salts. These salts then undergo a [4+2] cycloaddition in the presence of Me3Si−C≡CH and styrene to cleanly form unprecedented derivatives of 1-R-phosphabarrelenium salts. 相似文献