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Solid-state emissive biphenylene bridged bisaroyl-S,N-ketene acetals as distinct aggregation-induced enhanced emitters and fluorometric probes

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Aggregate 2021年第5期2卷 179-184页

作者： Lukas Biesen Thomas J.J.Muller institut fur Organische und Makromolekulare chemie Heinrich-Heine-Universitat DusseldorfDüsseldorfGermany

Biphenylene bridged bisaroyl-S,N-ketene acetals can be readily synthesized by a one-pot Masuda borylation-Suzuki arylation sequence,thus,yielding a library of 20 bisaroyl-S,N-ketene acetals with tunable solid-state emission and aggregationinduced enhanced emission characteristics depending on the para substituents in the starting *** applications as fluorometric probe of alcoholic beverages are outlined.

关键词： aggregation-induced emission aroyl-S N-ketene acetals liquor sensors one-pot reaction solid-state

Chapter model systems in heterogeneous catalysis at the atomic level: a personal view

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Science China Chemistry 2020年第4期63卷 426-447页

作者： Hans-Joachim Freund Markus Heyde Helmut Kuhlenbeck Niklas Nilius Thomas Risse Thomas Schmidt Shamil Shaikhutdinov Martin Sterrer Fritz Haber institute of the Max Planck Society Faradayweg 4-6Berlin D-14195Germany Fakultat V-Mathematik und Naturwissenschaften Carl von Ossietzky Universitat OldenburgGermany institut fur chemie und biochemie Freie UniversitatBerlinGermany institute of Physics University of GrazGrazAustria

The review presents an overview of studies in the surface science of oxide and related surfaces with an emphasis of the studies performed in the authors’ group. Novel instruments and technique developments, as well as their applications are reported, in an attempt to cover studies on model systems of increasing complexity, including some of the key ingredients of an industrially applied heterogeneous catalyst and its fabrication. The review is intended to demonstrate the power of model studies in understanding heterogeneous catalysis at the atomic level. The studies include those on supported nano-particles, both, prepared in vacuum and from solution, interaction of surfaces and the underlying bulk with molecules from the gas phase, strong metal support interaction, as well as the first attempt to include studies on reactions in confined spaces.

关键词： model catalysts oxide surfaces structure and spectroscopy supported nanoparticles reactions in the confined space

Cobaltaelectro-Catalyzed C—H Acyloxylation

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Chinese Journal of Chemistry 2019年第6期37卷 552-556页

作者： Cong Tian Uttam Dhawa Julia Struwe Lutz Ackermann institut fur Organische und Biomolekulare chemie Georg-August-Universitat GottingenTammannstraβe 237077 GottingenGermany

Cobaltaelectrocatalysis set the stage for sustainable C—H acyloxylations in biomass-derived γ-valerolactone as a renewable solvent. The sustainable electrocatalysis regime featured ample scope, along with high level... 详细信息

关键词： C-H activation cobalt electrosynthesis biomass solvent

Isotopic labelling experiments and enzymatic preparation of iso-casbenes with casbene synthase from Ricinus communis

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Organic Chemistry Frontiers 2022年第3期9卷 795-801页

作者： Heng Li Jeroen S.Dickschat Kekulé-institut für Organische chemie und biochemie Rheinische Friedrich-Wilhelms-Universität BonnGerhard-Domagk-Straße 153121 BonnGermany

Isotopic labelling experiments gave insights into the enzyme mechanism of casbene synthase from Ricinus communis,showing a clear stereochemical course for the cyclisation reaction,in agreement with the reported absolute configuration of *** oligoprenyl diphosphate analogs with shifted double bonds were synthesised and enzymatically converted with casbene synthase to yield casbene isomers.

关键词： enzymatic isomers bonds

ENVIRONMENTAL BEHAVIOR OF LINEAR ALKYLBENZENE SULFONATE (LAS) IN AQUATIC ECOSYSTEM

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Chinese Journal of Oceanology and Limnology 1991年第1期9卷 78-87页

作者：张甬元谭渝云 F.Korte institute of Hydrobiology Academia Sinica Wuhan 430072 Gesellschaft fur Strahlen-und Umweltforschung mbH Munchen institut fur Ukokogische chemie F.R. Germany

LAS degradation rate in Donghu Lake water under aerobic was much faster than under anaerobic condition . The half life of LAS in aerobic and anaerobic environment was 3.2 days and 57 days, respectively . The degradation rate at 25-27℃was approximately 20 times higher than that at 1.5-3.5℃.In a laboratory model aquatic ecosystem, two stages of bioconcentration in fish , daphnia and snail were observed . The first stage , on second day exposure , resulted from accumulation of intact LAS , and the second stage , on 16th day exposure , was due to metabolites . The bioconcentration factor (BCF) of LAS was extremely low in the muscle of hybrid carp (0.64), but rather high (2485) in the gall bladder .

关键词： anaerobic aquatic exposure degraded biodegradation digestion bladder intact extremely remove

Quantum model simulations of attosecond electron diffraction

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Science China(Physics,Mechanics & Astronomy) 2010年第6期53卷 987-1004页

作者： Peter BAUM Jrn MANZ Axel SCHILD Max-Planck-institute of Quantum Optics and Ludwig-Maximilians-Universitt München Freie Universitt Berlin Institut für Chemie und Biochemie

Ultrafast diffraction with free attosecond electron pulses promises insight into the four-dimensional motion of charge density inatoms,molecules and condensed matter. Here we consider the quantum dynamics of the electron-electron scattering process on anattosecond time scale. By numerically solving the time-dependent two-electron Schrdinger equation,we investigate the interactionof an incoming keV-range electron wavepacket by the bound electron of an aligned H+2 molecule,using a one-dimensional *** findings reveal the ratio of elastic to inelastic contributions,the role of exchange interaction,and the influence of the molecularelectron density to diffraction. Momentum transfer during the scattering process,from the incoming to the bound electron mediatedby the nuclei,leaves the bound electron in a state of coherent oscillation with attosecond recurrences. Entanglement causes relatedstate-selective oscillations in the phase shift of the scattered electron. Two scenarios of distinguishable and indistinguishable freeand bound electrons yield equivalent results,irrespective of the electronic spins. This suggests to employ the scenario of distinguishable electrons,which is computationally less demanding. Our findings support the possibility of using electron diffraction forimaging the motion of charge density,but also suggest the application of free electron pulses for inducing attosecond dynamics.

关键词： ultrafast electron diffraction scattering theory attosecond dynamics entanglement coherence

Condensation of pyrylium salts with mixed anhydrides:aryl ethers,aryl amines and sterically congested aromatics

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Organic Chemistry Frontiers 2022年第2期9卷 294-298页

作者： Daniel Grabowski Susanne Alef Steven Becker Ute Muller Gregor Schnakenburg Sigurd Hoger aKekulé-institut für Organische chemie und biochemie Rheinische Friedrich-Wilhelms-Universität BonnGerhard-Domagk-Str.153121 BonnGermany binstitut für Anorganische chemie Universität BonnGerhard-Domagk-Str.153121 BonnGermany

The condensation of easily accessible and widely functionalizable 2,4,6-triaryl pyrylium salts with mixed anhydrides,formed in situ fromα-functionalized sodium acetates and an anhydride solvent,leads in good yields to the corresponding 2,4,6-triaryl benzenes functionalized at their 1-position.4-(Trifluoromethyl)benzoic anhydride has been proven as being the solvent of choice and ortho-disubstituted diphenyl ethers,triphenyl amines and phenyl carbazoles with different functionalizations are *** addition,sterically hindered anthracene diacetate is condensed with two bis-bromophenyl pyrylium salts which leads after intramolecular Yamamoto coupling to *** these,the anthracene core is surrounded by phenylenes and protected from photooxidation,leading to a highly stable blue emitting material.

关键词： material. anhydride salts

Ionic liquids in electrocatalysis

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Journal of Energy Chemistry 2016年第2期25卷 197-205页

作者： Gui-Rong Zhang Bastian J.M.Etzold Lehrstuhl fur Chemische Reaktionstechnik Friedrich-Alexander-Universitat Erlangen-Nurnberg Erlangen 91058 Germany Ernst-Berl-institut fur Technische und Makromolekulare chemie Technische Universitat Darmstadt Darmstadt 64287 Germany

The performance of an electrocatalyst, which is needed e.g. for key energy conversion reactions such as hydrogen evolution, oxygen reduction or CO2 reduction, is determined not only by the inherent structure of active sites but also by the properties of the interfacial structures at catalytic surfaces. Ionic liquids（ILs）, as a unique class of metal salts with melting point below 100 ℃, present themselves as ideal modulators for manipulations of the interfacial structures. Due to their excellent properties such as good chemical stability, high ionic conductivity, wide electrochemical windows and tunable solvent properties the performance of electrocatalysts can be substantially improved through ILs. In the current minireview, we highlight the critical role of the IL phase at the microenvironments created by the IL, the liquid electrolyte, catalytic nanoparticles and/or support materials, by detailing the promotional effect of IL in electrocatalysis as reaction media, binders, and surface modifiers. Updated exemplary applications of IL in electrocatalysis are given and moreover, the latest developments of IL modified electrocatalysts following the ＂Solid Catalyst with Ionic Liquid Layer（SCILL）＂ concept are presented.

关键词： Electrocatalysis Ionic liquid Solid catalyst with ionic liquid layer Ligand effect Mass transfer Fuel cell Water electrolysis

Delayed allogeneic skin graft rejection in CD26-deficient mice

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Cellular & Molecular Immunology 2019年第6期16卷 557-567页

作者： Xiangli Zhao Kai Zhang Peter Daniel Natali Wisbrun Hendrik Fuchs Hua Fan institut fur Laboratoriumsmedizin Klinische Chemie und PathobiochemieCVKCharite-Universitatsmedizin BerlinBerlinGermany College of Food Science and Technology Shanghai Ocean UniversityShanghaiPR China Max-Delbrück-Center for Molecular Medicine BerlinGermany Leibniz-institut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V. BerlinGermany

Organ transplantation is an effective therapeutic tool for treating many terminal ***,one of the biggest challenges of transplantation is determining how to achieve the long-term survival of the allogeneic or xenogeneic transplant by,for example,preventing transplant *** the current study,CD26 gene-knockout mice were used to investigate the potential role of CD26/dipeptidyl peptidase-4(DPPIV)in allogeneic skin graft rejection by tail-skin *** with wild-type(CD26^(+/+))counterparts,CD26^(-/-)mice showed reduced necrosis of grafts and delayed graft rejection after skin *** of serum IgG,including its subclasses IgG1 and IgG2a,were significantly reduced in CD26^(-/-)mice during graft ***,after allogeneic skin transplantation,the secretion levels of the cytokines IFN-γ,IL-2,IL-6,IL-4,and IL-13 were significantly reduced,whereas the level of the cytokine IL-10 was increased in the serum of CD26^(-/-)mice compared with that in the serum of CD26^(+/+)***,the concentration of IL-17 in serum and the percentage of cells secreting IL-17 in mouse peripheral blood lymphocytes(MPBLs)were both significantly lower,while the percentage of regulatory T cells(Tregs)was significantly higher in MPBLs of CD26^(-/-)mice than in those of CD26^(+/+)***,a lower percentage of CD8^(+)T cells in MPBLs and fewer infiltrated macrophages and T cells in graft tissues of CD26^(-/-)mice were detected during graft *** results indicate that CD26 is involved in allogeneic skin graft rejection and provides another hint that CD26 deficiency leads to less rejection due to lower activation and proliferation of host immune cells.

关键词： Allogeneic graft rejection CD26/DPPIV Cytokine IgG T lymphocytes