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51.
Alkylated Aromatic Thioethers with Aggregation‐Induced Emission Properties—Assembly and Photophysics
Steffen Riebe Marco Saccone Jacqueline Stelzer Andrea Sowa Christoph Wlper Kateryna Soloviova Cristian A. Strassert Michael Giese Jens Voskuhl 《化学:亚洲杂志》2019,14(6):814-820
In this contribution, we present the synthesis and self‐assembly of alkylated thioethers with interesting photophysical properties. To this end, the emission, absorption and excitation spectra in organic solvents and as aggregates in water were measured as well as the corresponding photoluminescence quantum yields and lifetimes. The aggregates in aqueous media were visualized and measured using transmission electron microscopy. Besides that, crystal structures of selected compounds allowed a detailed discussion of the structure–property relationship. Furthermore, the mesomorphic behavior was investigated using polarized optical microscopy (POM) as well as differential scanning calorimetry (DSC). 相似文献
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Dr. Haifeng Xiong Dr. Sen Lin Joris Goetze Dr. Paul Pletcher Prof. Dr. Hua Guo Dr. Libor Kovarik Dr. Kateryna Artyushkova Prof. Dr. Bert M. Weckhuysen Prof. Dr. Abhaya K. Datye 《Angewandte Chemie (International ed. in English)》2017,56(31):8986-8991
Ceria (CeO2) supports are unique in their ability to trap ionic platinum (Pt), providing exceptional stability for isolated single atoms of Pt. The reactivity and stability of single-atom Pt species was explored for the industrially important light alkane dehydrogenation reaction. The single-atom Pt/CeO2 catalysts are stable during propane dehydrogenation, but are not selective for propylene. DFT calculations show strong adsorption of the olefin produced, leading to further unwanted reactions. In contrast, when tin (Sn) is added to CeO2, the single-atom Pt catalyst undergoes an activation phase where it transforms into Pt–Sn clusters under reaction conditions. Formation of small Pt–Sn clusters allows the catalyst to achieve high selectivity towards propylene because of facile desorption of the product. The CeO2-supported Pt–Sn clusters are very stable, even during extended reaction at 680 °C. Coke formation is almost completely suppressed by adding water vapor to the feed. Furthermore, upon oxidation the Pt–Sn clusters readily revert to the atomically dispersed species on CeO2, making Pt–Sn/CeO2 a fully regenerable catalyst. 相似文献
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Dr. Olena Vakuliuk Dr. Yong Woong Jun Kateryna Vygranenko Guillaume Clermont Ye Jin Reo Dr. Mireille Blanchard-Desce Prof. Kyo Han Ahn Prof. Dr. Daniel T. Gryko 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(58):13354-13362
New L -shaped fluorophores possessing five conjugated rings have been synthesized through a four-step procedure involving diketopyrrolopyrrole synthesis and its double N-alkylation, followed by trimethylsilyl bromide-mediated rearrangement to thieno[2,3-f]isoindole-5,8-dione and an intramolecular Friedel–Crafts reaction. In comparison with the parent isoindolediones and π-expanded diketopyrrolopyrroles, these new dyes show red-shifted absorption and emission (up to ≈630 nm). Their structural rigidity is responsible for both the observed small Stokes shifts and large fluorescence quantum yields. Tissue imaging studies revealed that these new dyes show advantageous features including minimal autofluorescence interference and pronounced solvent-sensitive emission. Interestingly, there is a fundamental difference between a dye possessing an amino group and its analog bearing an N-alkyl substituent. The former dye under two-photon excitation at 900 nm gives bright images whereas its N-alkylated counterpart does not. A new type of membrane localization has been discovered by an N-alkylated isoindoledione possessing a benzofuryl substituent. In spite of the fact that the fluorescence quantum yield of this dye in a range of solvents is rather low, it does stain cell membranes exclusively. This new mode of cellular staining opens the door towards further development of membrane staining dyes. 相似文献
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Sarah Salloum Dr. Georg Bendt Dr. Markus Heidelmann Dr. Kateryna Loza Samaneh Bayesteh M. Sepideh Izadi Patrick Kawulok Dr. Ran He Dr. Heike Schlörb Dr. Nicolas Perez Dr. Heiko Reith Prof. Dr. Kornelius Nielsch Prof. Dr. Gabi Schierning Prof. Dr. Stephan Schulz 《ChemistryOpen》2021,10(2):189-198
The synthesis of phase-pure ternary solutions of tetradymite-type materials (BixSb1−x)2Te3 (x=0.25; 0.50; 0.75) in an ionic liquid approach has been carried out. The nanoparticles are characterized by means of energy-dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and transmission electron microscopy. In addition, the role of different processing approaches on the thermoelectric properties - Seebeck coefficient as well as electrical and thermal conductivity - is demonstrated. 相似文献
56.
Kateryna V. Terebilenko Alexander A. Kirichok Maksym Sereduk P. Gütlich 《Journal of solid state chemistry》2010,183(6):1473-1476
AgFeP2O7 has been synthesized by flux crystallization and characterized by single crystal and powder X-ray diffraction (sp. gr. P21/c, a=7.3298(2), b=7.9702(2), c=9.5653(2) Å, β=111.842(1)°, V=518.68(2) Å3) and FTIR-spectroscopy. The structure is composed of isolated iron octahedra and phosphate tetrahedra interconnected into 3D network with hexagonal channels, where silver counter-ions are located. The magnetic behavior of the compound approaches the Curie-Weiss equation with a Weiss constant θ=−165.9 K indicating strong antiferromagnetic interaction between iron(III) ions. 相似文献
57.
Dounia zed Mezdour Mohamed Tabellout Salah Sahli Kateryna Fatyeyeva 《Macromolecular Symposia》2010,290(1):15-24
Summary: Volume conducting PA-12 based composites powders were chemically prepared by in situ polymerization and aniline doping at room temperature. These kinds of polyamide / PANI composites were investigated regarding their electrical properties. Their ac and dc electrical properties measured in the frequency range of 10−2–107 Hz are reported and the frequency dependence of electrical conductivity was investigated as a function of PANI concentration leading to the determination of the conductivity. The experimental conductivity was found to increase continuously with PANI content and explained by percolation theory with a relatively low percolation threshold of about 0.4 wt.%. The dielectric behavior of various PANI polymer composites has been characterized by the critical frequency ωc (denoting the crossover from the dc plateau of the conductivity to its frequency dependent ac behaviour). Modelling the conductivity behavior versus volume fraction using Slupkowski approach has revealed that the considered parameters are not sufficient to describe the electrical conductivity behavior. 相似文献
58.
Kostenko OM Kovalska VB Volkova KD Shaytanov P Kocheshev IO Slominskiy YL Pisareva IV Yarmoluk SM 《Journal of fluorescence》2006,16(4):589-593
Fluorescent chromophore, alkylamino-(tetra-hydronaphthalenylidene)- benzothiazolium derivatives (HBTN dyes), are proposed as covalent labels for proteins via aliphatic amino groups. Spectral-luminescent properties of 3-methyl-2-{(E)-[7-(methylamino)-4,4a,5,6-tetra-hydronaphthalen-2(3H)-ylidene]methyl}-1,3-benzothiazol-3-ium chloride (HBTN, R=Me) and its predecessor, 2-[(E)-(7-methoxy-4,4a,5,6-tetrahydronaphthalen-2(3H)-ylidene)methyl]-3-methyl-1,3-benzothia-zol-3-ium chloride (ABTN), are studied for free dyes and in the presence of DNA and BSA. Considerable spectral-luminescent changes accompany the transformation of ABTN into HBTN that allows monitoring conjugation reaction. In presence of DNA and BSA the HBTN increases its emission in 15 and 4 times respectively and becomes strongly fluorescent. The conditions for labeling are developed and a model conjugate of HBTN dye with BSA is synthesized. It was shown that using of HBTN dye as a fluorescent label allows detection by eye of about 3 μg/band of BSA on polyacrylamide gel upon UV-irradiation. 相似文献
59.
Carlo Santoro Alexey Serov Kateryna Artyushkova Plamen Atanassov 《Current Opinion in Electrochemistry》2020
The oxygen reduction reaction is one of the limiting steps in microbial fuel cell performance. M–N–C catalysts (M as transition metal) represent the best compromise of optimal cost, electrocatalytic activity and durability. The Fe-based catalysts were shown to be the best compared with Co-, Mn-, Ni-based catalysts. The addition of the second transition metal such as Mn was shown to increase the selectivity of the reaction and reduce peroxide production. The use of different N–C precursors resulted in diverse surface chemistry that directly affects the performance. Generally, surface chemistry plays a critical role in the electrocatalytic activity. Integration of the catalyst in the air-breathing cathode is also discussed with a performance that is enhanced by: (i) increased catalyst loading; (ii) the addition of graphene to structure. 相似文献