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111.
Tetiana Krachko Mark Bispinghoff Dr. Aaron M. Tondreau Dr. Daniel Stein Matthew Baker Dr. Andreas W. Ehlers Prof. Dr. J. Chris Slootweg Prof. Dr. Hansjörg Grützmacher 《Angewandte Chemie (International ed. in English)》2017,56(27):7948-7951
Phosphinidenes [R-P] are convenient P1 building blocks for the synthesis of a plethora of organophosphorus compounds. Thus far, transition-metal-complexed phosphinidenes have been used for their singlet ground-state reactivity to promote selective addition and insertion reactions. One disadvantage of this approach is that after transfer of the P1 moiety to the substrate, a challenging demetallation step is required to provide the free phosphine. We report a simple method that enables the Lewis acid promoted transfer of phenylphosphinidene, [PhP], from NHC=PPh adducts (NHC=N-heterocyclic carbene) to various substrates to produce directly uncoordinated phosphorus heterocycles that are difficult to obtain otherwise. 相似文献
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Siwei Wang Jesse Ward Sven Leyffer Stefan M. Wild Chris Jacobsen Stefan Vogt 《Journal of synchrotron radiation》2014,21(3):568-579
A novel approach to locate, identify and refine positions and whole areas of cell structures based on elemental contents measured by X‐ray fluorescence microscopy is introduced. It is shown that, by initializing with only a handful of prototypical cell regions, this approach can obtain consistent identification of whole cells, even when cells are overlapping, without training by explicit annotation. It is robust both to different measurements on the same sample and to different initializations. This effort provides a versatile framework to identify targeted cellular structures from datasets too complex for manual analysis, like most X‐ray fluorescence microscopy data. Possible future extensions are also discussed. 相似文献
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Jonathan T. Reeves Zhulin Tan Bruce Z. Lu Chris H. Senanayake 《Journal of heterocyclic chemistry》2013,50(3):680-683
Various 2‐formylazoles underwent CuI/sparteine‐catalyzed annulation with 1‐substituted‐4‐iodo‐5‐aminopyrazoles to produce four new heterocyclic ring systems. The reaction was demonstrated for 2‐formylpyrroles, 2‐formylindoles, 2‐formylimidazole, and 3‐methyl‐5‐formylpyrazole. 3‐Substitution of the iodopyrazole was tolerated. 相似文献
116.
Layered Black Phosphorus: Strongly Anisotropic Magnetic,Electronic, and Electron‐Transfer Properties
Zdenk Sofer David Sedmidubský tpn Huber Jan Luxa Daniel Boua Chris Boothroyd Martin Pumera 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(10):3443-3447
Layered elemental materials, such as black phosphorus, exhibit unique properties originating from their highly anisotropic layered structure. The results presented herein demonstrate an anomalous anisotropy for the electrical, magnetic, and electrochemical properties of black phosphorus. It is shown that heterogeneous electron transfer from black phosphorus to outer‐ and inner‐sphere molecular probes is highly anisotropic. The electron‐transfer rates differ at the basal and edge planes. These unusual properties were interpreted by means of calculations, manifesting the metallic character of the edge planes as compared to the semiconducting properties of the basal plane. This indicates that black phosphorus belongs to a group of materials known as topological insulators. Consequently, these effects render the magnetic properties highly anisotropic, as both diamagnetic and paramagnetic behavior can be observed depending on the orientation in the magnetic field. 相似文献
117.
Ten bis(4-aryloxy-3-nitrophenyl) sulfones were synthesized via a phase-transfer catalyzed, nucleophilic displacement reaction involving phenoxides and bis(4-chloro-3-nitrophenyl) sulfone. 相似文献
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Johan Sjöblom Hege Ebeltoft Alf Bjørseth Stig E. Friberg Chris Brancewicz 《Journal of Dispersion Science and Technology》2013,34(1):21-34
Hydrolysis and condensation of monomolecular alkyloxysilane films by the Langmuir technique is presented. Octadecyltrimethoxysilane formed monolayers on aqueous subphases with different properties depending on the bulk pH. At pH 1 a solid condensed film was directly formed with a molecular area of 23 Å2 and a surface pressure/surface area variation similar to that on non-ionized stearic acid. At pH 5.6 and 11 several phase transitions were observed during the compression of the monolayer with a final collapse at a molecular area of 20 Å2. Relaxation measurements confirmed the stability of the films for longer than 12 hours at different surface pressures below a critical value. 相似文献
120.