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1.
We establish a theory of Q -valued functions minimizing a suitable generalization of the Dirichlet integral. In a second paper the theory will be used to approximate efficiently area minimizing currents mod(p) when p = 2Q , and to establish a first general partial regularity theorem for every p in any dimension and codimension . © 2020 Wiley Periodicals LLC. 相似文献
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Dr. Bugga Balakrishna Arjun Menon Dr. Kecheng Cao Sebastian Gsänger Dr. Sebastian B. Beil Julia Villalva Oleksandr Shyshov Oliver Martin Prof. Dr. Andreas Hirsch Prof. Dr. Bernd Meyer Prof. Dr. Ute Kaiser Prof. Dr. Dirk M. Guldi Prof. Dr. Max von Delius 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(42):18933-18945
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Mayara da Silva Santos Dr. Robert Medel Max Flach Olesya S. Ablyasova Martin Timm Prof. Dr. Bernd von Issendorff Dr. Konstantin Hirsch Dr. Vicente Zamudio-Bayer Prof. Dr. Sebastian Riedel Prof. Dr. J. Tobias Lau 《Chemphyschem》2023,24(22):e202300390
The tetraoxido ruthenium(VIII) radical cation, [RuO4]+, should be a strong oxidizing agent, but has been difficult to produce and investigate so far. In our X-ray absorption spectroscopy study, in combination with quantum-chemical calculations, we show that [RuO4]+, produced via oxidation of ruthenium cations by ozone in the gas phase, forms the oxygen-centered radical ground state. The oxygen-centered radical character of [RuO4]+ is identified by the chemical shift at the ruthenium M3 edge, indicative of ruthenium(VIII), and by the presence of a characteristic low-energy transition at the oxygen K edge, involving an oxygen-centered singly-occupied molecular orbital, which is suppressed when the oxygen-centered radical is quenched by hydrogenation of [RuO4]+ to the closed-shell [RuO4H]+ ion. Hydrogen-atom abstraction from methane is calculated to be only slightly less exothermic for [RuO4]+ than for [OsO4]+. 相似文献
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Based on rational design of the transition state analog inhibitors of glycosyltransferases, four model glycomimetics of this type, viz. benzyl 2-thio-α-dfructofuranoside 1-diethylphosphate (XIa), its β-anomer (XIb), and their ethyl 2-thio analogs — α-anomer (XIIa) and β-anomer (XIIb), were synthesized. In addition, fourteen precursors arising during the synthesis of the desired final model compounds (XI and XII), partially or fully acetylated benzyl and/or ethyl 2-thiofructofuranoside 1-diethyl phosphates, were isolated and characterized with the aim to prepare complete series of glycomimetics, representing donor UDP-GlcNAc designated for biological assays on human GnT’s, viz. GnT-I, Core2GnT, and GnT-V. 相似文献
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Very Facile Polarity Umpolung and Noncovalent Functionalization of Inorganic Nanoparticles: A Tool Kit for Supramolecular Materials Chemistry 下载免费PDF全文
Lukas Zeininger Stefanie Petzi Jörg Schönamsgruber Luis Portilla Prof. Dr. Marcus Halik Prof. Dr. Andreas Hirsch 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(40):14030-14035
The facile assembly of shell‐by‐shell (SbS)‐coated nanoparticles [TiO2?PAC16]@shell 1 – 7 (PAC16=hexadecylphosphonic acid), which are soluble in water and can be isolated as stable solids, is reported. In these functional architectures, an umpolung of dispersibility (organic apolar versus water) was accomplished by the noncovalent binding of ligands 1 – 7 to titania nanoparticles [TiO2?PAC16] containing a first covalent coating with PAC16. Ligands 1 – 7 are amphiphilic and form the outer second shell of [TiO2?PAC16]@shell 1 – 7 . The tailor‐designed dendritic building blocks 3 – 5 contain negative and positive charges in the same molecule, and ligands 6 and 7 contain a perylenetetracarboxylic acid dimide (PDI) core ( 6 / 7 ) as a photoactive reporter component. In the redox and photoactive system [TiO2?PAC16]@shell 7 , electronic communication between the inorganic core to the PDI ligands was observed. 相似文献
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Dmitry Sharapa Prof. Andreas Hirsch Prof. Bernd Meyer Prof. Timothy Clark 《Chemphyschem》2015,16(10):2165-2171
Ab initio and DFT calculations are used to investigate the structure, electronic properties, spectra and reactivity of cubic C8, which is predicted to be aromatic according to Hirsch′s rule. Although highly strained and with a small amount of diradical character, the carbon cube represents a surprisingly deep minimum and should therefore be observable as an isolated molecule. It is, however, predicted to be very reactive, both with itself and triplet oxygen. Calculated IR, Raman, and UV/Vis spectra are provided to aid identification of cubic C8 should it be synthesized. 相似文献
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Konstantin Dirian Susanne Backes Claudia Backes Volker Strauss Fabian Rodler Frank Hauke Andreas Hirsch Dirk M. Guldi 《Chemical science》2015,6(12):6886-6895
A water soluble naphthalenebisimide derivative (NBI) was synthesized and probed to individualize, suspend, and stabilize single wall carbon nanotubes (SWCNTs). Besides a comprehensive photophysical and electrochemical characterization of NBI, stable suspensions of SWCNTs were realized in buffered D2O. Overall, the dispersion efficiency of the NBI surfactant was determined by comparison with naphthalene based references. Successful individualization of SWCNTs was corroborated in several microscopic assays. In addition, emission spectroscopy points to the strong quenching of SWCNT centered band gap emission, when NBIs are immobilized onto SWCNTs. The origin of the quenching was found to be strong electronic communication, which leads to charge separation between NBIs and photoexcited SWCNTs, and, which yields reduced NBIs as well oxidized SWCNTs. Notably, electrochemical considerations revealed that the energy content of these charge separated states is one of the highest reported for SWCNT based electron donor–acceptor hybrids so far. 相似文献