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1.
Viktoriia Morad Dr. Michael Wörle Dr. Sergii Yakunin Dr. Gabriele Rainò Olga Nazarenko Markus Fischer Dr. Ivan Infante Prof. Dr. Maksym V. Kovalenko 《Angewandte Chemie (International ed. in English)》2018,57(35):11329-11333
The spatial localization of charge carriers to promote the formation of bound excitons and concomitantly enhance radiative recombination has long been a goal for luminescent semiconductors. Zero‐dimensional materials structurally impose carrier localization and result in the formation of localized Frenkel excitons. Now the fully inorganic, perovskite‐derived zero‐dimensional SnII material Cs4SnBr6 is presented that exhibits room‐temperature broad‐band photoluminescence centered at 540 nm with a quantum yield (QY) of 15±5 %. A series of analogous compositions following the general formula Cs4?xAxSn(Br1?yIy)6 (A=Rb, K; x≤1, y≤1) can be prepared. The emission of these materials ranges from 500 nm to 620 nm with the possibility to compositionally tune the Stokes shift and the self‐trapped exciton emission bands. 相似文献
2.
Mingze Li Jun Zhou Guojun Zhou Maxim S. Molokeev Jing Zhao Viktoriia Morad Maksym V. Kovalenko Zhiguo Xia 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(51):18843-18848
Very little is known about the realm of solid‐state metal halide compounds comprising two or more halometalate anions. Such compounds would be of great interest if their optical and electronic properties could be rationally designed. Herein, we report a new example of metal halide cluster‐assembled compound (C9NH20)9[Pb3Br11](MnBr4)2, featuring distinctly different anionic polyhedra, namely, a rare lead halide cluster [Pb3Br11]5? and [MnBr4]2?. In accordance with its multinary zero‐dimensional (0D) structure, this compound is found to contain two distinct emission centers, 565 nm and 528 nm, resulting from the formation of self‐trapped excitons and 4T1‐6A1 transition of Mn2+ ions, respectively. Based on the high durability of (C9NH20)9[Pb3Br11](MnBr4)2 upon light and heat, as well as high photoluminescence quantum yield (PLQY) of 49.8 % under 450 nm blue light excitation, white light‐emitting diodes (WLEDs) are fabricated, showcasing its potential in backlight application. 相似文献
3.
Oleksandr P. Demchuk Bohdan V. Bobovskyi Bohdan V. Vashchenko Dr. Oleksandr V. Hryshchuk Artem Skreminskyi Dr. Anton V. Chernykh Dr. Viktoriia S. Moskvina Dr. Olga V. Hordiyenko Prof. Dr. Dmitriy M. Volochnyuk Prof. Dr. Oleksandr O. Grygorenko 《European journal of organic chemistry》2023,26(24):e202300292
Synthesis and physicochemical characterization of all possible cis- and trans-1,3-disubstituted cyclobutane-derived amines and carboxylic acids bearing mono-, di- and trifluoromethyl groups at the C-3 position is disclosed. Tetramethylammonium fluoride (TMAF)- or morpholinosulfur trifluoride (Morph-DAST)-mediated nucleophilic fluorination of appropriate cis- and trans-diastereomeric substrates was used as the key step for the preparation of CH2F- and CHF2-substituted derivatives. To obtain the corresponding cis- and trans-isomeric CF3-substituted derivatives, resolution of known 3-(trifluoromethyl)cyclobutanecarboxylic acid (obtained as a mixture of diastereomers) was applied. The proposed procedures were suitable for the preparation of corresponding fluoroalkyl-substituted cyclobutane-derived amines and carboxylic acids on up to 50 g scale. All 12 building blocks obtained were characterized by measuring dissociation constants (pKa) and lipophilicities (LogP, for model derivatives) to evaluate the effect of the fluoroalkyl substituents on their physicochemical properties relevant to further drug discovery applications. 相似文献
4.
The mechanisms responsible for enhanced transmission of electromagnetic wave through an array of subwavelength slits in a metallic film are analyzed. Theoretical model of the enhanced transmission which takes into account the penetration of electromagnetic field into real metal is developed. Semi-analytical model based on Fabry–Perot formula is considered. Comparison of theoretical model, semi-analytical model and results of numerical simulation of Maxwell equations in time-dependent form (FDTD method) for silver with various geometric parameters is presented. The roles of surface plasmons and plasmon localized along slits are studied. 相似文献
5.
Malets Yehor S. Moskvina Viktoriia S. Grygorenko Oleksandr O. Brovarets Volodymyr S. 《Chemistry of Heterocyclic Compounds》2019,55(11):1007-1012
Chemistry of Heterocyclic Compounds - This minireview highlights known methods for the synthesis of azachromones and azachromanones, including the earliest and the latest examples of their... 相似文献
6.
Marcel Aebli Bogdan M. Benin Kyle M. McCall Viktoriia Morad Debora Thöny Hansjörg Grützmacher Maksym V. Kovalenko 《Helvetica chimica acta》2020,103(7):e2000080
Inorganic lead halide perovskites have gained immense scientific interest for optoelectronic applications. In this work, we present a one-dimensional polymorph of cesium lead bromide (δ-CsPbBr3) synthesized through a simple anion-exchange reaction, wherein distorted edge-sharing PbBr6 octahedra form 1D chains isolated by Cs ions. δ-CsPbBr3 was characterized by Raman spectroscopy, X-ray diffraction, 207Pb and 133Cs solid-state NMR, and by optical emission and absorption spectroscopies. This non-perovskite material irreversibly transforms into the well-known three-dimensional perovskite phase (γ-CsPbBr3) upon heating to above 151 °C. The indirect bandgap was determined by absorption measurements and calculation to be 2.9 eV. δ-CsPbBr3 exhibits broadband yellow photoluminescence with a quantum yield of 3.2 %±0.2 % at room temperature and 95 %±5 % at 77 K, and this emission is attributed to the recombination of self-trapped excitons. This study emphasizes that the metastable δ-CsPbBr3 may be a persistent, concomitant phase in Cs−Pb-Br-containing materials systems, such as those used in solar cells and LEDs, and it showcases the characterization tools used for its detection. 相似文献
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Pivovarenko VG Zamotaiev OM Shvadchak VV Postupalenko VY Klymchenko AS Mély Y 《The journal of physical chemistry. A》2012,116(12):3103-3109
By using four labels of the 3-hydroxyflavone family displaying selective sensitivity to hydrogen bond (HB) donors and poor response to other polar molecules, we developed an approach for measuring local water concentration [H(2)O](L) (or partial volume of water: W(A) = [H(2)O](L)/55.6) in the label surrounding both in solvent mixtures and in biomolecules by the intensity ratio of two emissive forms of the label, N*/T*. Using a series of binary water/solvent mixtures with limited preferential solvation effects, a linear dependence of log(N*/T*) on the local concentration of HB donor was obtained and then used as a calibration curve for estimating the W(A) values in the surroundings of the probes conjugated to biomolecules. By this approach, we estimated the hydration of the labels in different peptides and their complexes with DNAs. We found that W(A) values for the label at the peptide N-terminus are lower (0.63-0.91) than for free labels and depend strongly on the nature of the N-terminal amino acid. When complexed with different DNAs, the estimated hydration of the labels conjugated to the labeled peptides was much lower (W(A) = 0-0.47) and depended on the DNA nature and linker-label structure. Thus, the elaborated method allows a site-specific evaluation of hydration at the surface of a biomolecule through the determination of the partial volume of water. We believe the developed procedure can be successfully applied for monitoring hydration at the surface of any biomolecule or nanostructure. 相似文献
9.
Bogdan M. Benin Dr. Kyle M. McCall Dr. Michael Wörle Viktoriia Morad Marcel Aebli Dr. Sergii Yakunin Dr. Yevhen Shynkarenko Prof. Dr. Maksym V. Kovalenko 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(34):14598-14605
Low-dimensional ns2-metal halide compounds have received immense attention for applications in solid-state lighting, optical thermometry and thermography, and scintillation. However, these are based primarily on the combination of organic cations with toxic Pb2+ or unstable Sn2+, and a stable inorganic luminescent material has yet to be found. Here, the zero-dimensional Rb7Sb3Cl16 phase, comprised of isolated [SbCl6]3− octahedra and edge-sharing [Sb2Cl10]4− dimers, shows room-temperature photoluminescence (RT PL) centered at 560 nm with a quantum yield of 3.8±0.2 % at 296 K (99.4 % at 77 K). The temperature-dependent PL lifetime rivals that of previous low-dimensional materials with a specific temperature sensitivity above 0.06 K−1 at RT, making it an excellent thermometric material. Utilizing both DFT and chemical substitution with Bi3+ in the Rb7Bi3−3xSb3xCl16 (x≤1) family, we present the edge-shared [Sb2Cl10]4− dimer as a design principle for Sb-based luminescent materials. 相似文献
10.
Yevheniia Husak Joanna Michalska Oleksandr Oleshko Viktoriia Korniienko Karlis Grundsteins Bohdan Dryhval Sahin Altundal Oleg Mishchenko Roman Viter Maksym Pogorielov Wojciech Simka 《Molecules (Basel, Switzerland)》2021,26(7)
The biodegradable metals, including magnesium (Mg), are a convenient alternative to permanent metals but fast uncontrolled corrosion limited wide clinical application. Formation of a barrier coating on Mg alloys could be a successful strategy for the production of a stable external layer that prevents fast corrosion. Our research was aimed to develop an Mg stable oxide coating using plasma electrolytic oxidation (PEO) in silicate-based solutions. 99.9% pure Mg alloy was anodized in electrolytes contained mixtures of sodium silicate and sodium fluoride, calcium hydroxide and sodium hydroxide. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), contact angle (CA), Photoluminescence analysis and immersion tests were performed to assess structural and long-term corrosion properties of the new coating. Biocompatibility and antibacterial potential of the new coating were evaluated using U2OS cell culture and the gram-positive Staphylococcus aureus (S. aureus, strain B 918). PEO provided the formation of a porous oxide layer with relatively high roughness. It was shown that Ca(OH)2 was a crucial compound for oxidation and surface modification of Mg implants, treated with the PEO method. The addition of Ca2+ ions resulted in more intense oxidation of the Mg surface and growth of the oxide layer with a higher active surface area. Cell culture experiments demonstrated appropriate cell adhesion to all investigated coatings with a significantly better proliferation rate for the samples treated in Ca(OH)2-containing electrolyte. In contrast, NaOH-based electrolyte provided more relevant antibacterial effects but did not support cell proliferation. In conclusion, it should be noted that PEO of Mg alloy in silicate baths containing Ca(OH)2 provided the formation of stable biocompatible oxide coatings that could be used in the development of commercial degradable implants. 相似文献