30 research outputs found
Giant anisotropy of Gilbert damping in a Rashba honeycomb antiferromagnet
Giant Gilbert damping anisotropy is identified as a signature of strong
Rashba spin-orbit coupling in a two-dimensional antiferromagnet on a honeycomb
lattice. The phenomenon originates in spin-orbit induced splitting of
conduction electron subbands that strongly suppresses certain spin-flip
processes. As a result, the spin-orbit interaction is shown to support an
undamped non-equilibrium dynamical mode that corresponds to an ultrafast
in-plane N\'eel vector precession and a constant perpendicular-to-the-plane
magnetization. The phenomenon is illustrated on the basis of a two dimensional
- like model. Spin-orbit torques and conductivity are also computed
microscopically for this model. Unlike Gilbert damping these quantities are
shown to reveal only a weak anisotropy that is limited to the semiconductor
regime corresponding to the Fermi energy staying in a close vicinity of
antiferromagnetic gap.Comment: 12 pages, 3 figure
Comprehensive lipidomic analysis of human plasma using multidimensional liquid- and gas-phase separations: Two-dimensional liquid chromatography-mass spectrometry <i>vs</i>. liquid chromatography-trapped-ion-mobility-mass spectrometry
Π‘ΠΈΠ½ΡΠ΅Π· 1-(ΡΡΠΈΠ΅ΡΠΈΠ»ΡΠΈΠ»ΡΠ»)-3-[4-(Π³Π΅ΡΠ°ΡΠΈΠ»)ΡΠ΅Π½ΡΠ»]- 5-(ΡΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΈΠ»ΡΠ»)ΠΏΠ΅Π½ΡΠ°-1,4-Π΄ΡΡΠ½-3-ΠΎΠ»ΡΠ²
The method of synthesis of 1-(triethylsilyl)-3-[4-(hetaryl)phenyl]-5-(trimethylsilyl)penta-1,4-diyn-3-ols based on the interaction between 1-(triethylsilyl)-5-(trimethylsilyl)penta-1,4-diyn-3-one and lithium derivatives of 1-(4-bromophenyl)-1H-indole or 9-(4-bromophenyl)-9H-carbazole has been developed.Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½ ΠΌΠ΅ΡΠΎΠ΄ ΡΠΈΠ½ΡΠ΅Π·Π° 1-(ΡΡΠΈΡΡΠΈΠ»ΡΠΈΠ»ΠΈΠ»)-3-[4-(Π³Π΅ΡΠ°ΡΠΈΠ»)ΡΠ΅Π½ΠΈΠ»]-5-(ΡΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΈΠ»ΠΈΠ»)ΠΏΠ΅Π½ΡΠ°-1,4-Π΄ΠΈΠΈΠ½-3-ΠΎΠ»ΠΎΠ², ΠΎΡΠ½ΠΎΠ²Π°Π½Π½ΡΠΉ Π½Π° Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΠΈ Π»ΠΈΡΠΈΠ΅Π²ΡΡ
ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΡΡ
1-(4-Π±ΡΠΎΠΌΡΠ΅Π½ΠΈΠ»)-1Π-ΠΈΠ½Π΄ΠΎΠ»Π° ΠΈ 9-(4-Π±ΡΠΎΠΌΡΠ΅Π½ΠΈΠ»)-9Π-ΠΊΠ°ΡΠ±Π°Π·ΠΎΠ»Π° Ρ 1-(ΡΡΠΈΡΡΠΈΠ»ΡΠΈΠ»ΠΈΠ»)-5-(ΡΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΈΠ»ΠΈΠ»)ΠΏΠ΅Π½ΡΠ°-1,4-Π΄ΠΈΠΈΠ½-3-ΠΎΠ½ΠΎΠΌ.Π ΠΎΠ·ΡΠΎΠ±Π»Π΅Π½ΠΎ ΠΌΠ΅ΡΠΎΠ΄ ΡΠΈΠ½ΡΠ΅Π·Ρ 1-(ΡΡΠΈΠ΅ΡΠΈΠ»ΡΠΈΠ»ΡΠ»)-3-[4-(Π³Π΅ΡΠ°ΡΠΈΠ»)ΡΠ΅Π½ΡΠ»]-5-(ΡΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΈΠ»ΡΠ»)ΠΏΠ΅Π½ΡΠ°-1,4-Π΄ΡΡΠ½-3-ΠΎΠ»ΡΠ², ΡΠΎ Π±Π°Π·ΡΡΡΡΡΡ Π½Π° Π²Π·Π°ΡΠΌΠΎΠ΄ΡΡ Π»ΡΡΡΡΠ²ΠΈΡ
ΠΏΠΎΡ
ΡΠ΄Π½ΠΈΡ
1-(4-Π±ΡΠΎΠΌΠΎΡΠ΅Π½ΡΠ»)-1Π-ΡΠ½Π΄ΠΎΠ»Ρ ΡΠ° 9-(4-Π±ΡΠΎΠΌΠΎΡΠ΅Π½ΡΠ»)-9Π-ΠΊΠ°ΡΠ±Π°Π·ΠΎΠ»Ρ Π· 1-(ΡΡΠΈΠ΅ΡΠΈΠ»ΡΠΈΠ»ΡΠ»)-5-(ΡΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΈΠ»ΡΠ»)ΠΏΠ΅Π½ΡΠ°-1,4-Π΄ΡΡΠ½-3-ΠΎΠ½ΠΎΠΌ
Combining incompatible processes for deracemization of Praziquantel derivative under flow conditions
An efficient deracemization method for conversion of the racemate to the desirable (R)-enantiomer of Praziquantel has been developed by coupling incompatible racemization and crystallization processes. By a library approach, a derivative that crystallizes as a conglomerate has been identified. Racemization occurs via reversible hydrogenation over a palladium on carbon (Pd/C) packed column at 130 Β°C, whereas deracemization is achieved by alternating crystal growth/dissolution steps with temperature cycling between 5β15 Β°C. These incompatible processes are combined by means of a flow system resulting in complete deracemization of the solid phase to the desired (R)-enantiomer (98 % ee). Such an unprecedented deracemization by a decoupled crystallization/racemization approach can readily be turned into a practical process and opens new opportunities for the development of essential enantiomerically pure building blocks that require harsh methods for racemization
The Creation of a New System of Labor Relations in Russia Theses
In and of itself, the title of this paper requires clarification: strictly speaking, a system of labor relations does not as yet exist in Russia. The country is at the stage of making the transition from the old, administrative system to the new, market system. This system is in large measure created not from internal conditions but through borrowings from foreign experience. The borrowings are eclectic, from different systems, and lack any understanding of the wholeness and historical logic in every country.
Rapid deracemization through solvent cycling:proof-of-concept using a racemizable conglomerate clopidogrel precursor
We demonstrate that a conglomerate-forming clopidogrel precursor undergoing solution phase racemization can be deracemized through cyclic solvent removal and re-addition. We establish that the combination of slow growth and fast dissolution of crystals is ideal for rapid deracemization, which we achieve by repurposing a Soxhlet apparatus to realize the slow removal and fast re-addition of solvent autonomously.</p
Counteracting Enantiospecific Behavior of Tailor-Made Additives During Chiral Symmetry Breaking: Growth Inhibition versus Solid-Solution Formation
Performance Analysis and Model-Free Design of Deracemization via Temperature Cycles
Solid-state deracemization via temperature cycles is a technique that has been shown to be effective to isolate the pure enantiomer of a conglomerate-forming compound. This process has a large number of operating parameters that can be adjusted according to system-specific properties. On the one hand, this feature makes the process flexible and prone to optimization. On the other hand, the design space is so large that experimental optimization of the process can become long and cumbersome. In this work, we achieve two results. First, we show that deracemization via temperature cycles works very effectively for two new experimental systems, namely, the chiral compounds 2-(benzylideneamino)-2-(2-chlorophenyl)acetamide (CPG) and 3,3-dimethyl-2-((naphthalen-2-ylmethylene)amino)butanenitrile (tLEU). Second, we propose a new approach for the design of an effective deracemization process via temperature cycles for a new compound. Therefore, in this work, we investigate the effect of different operating conditions, namely, the initial enantiomeric excess, the cooling rate, the temperature range, and the catalyst concentration, on the performance of deracemization via temperature cycles for the new compounds CPG and tLEU and for N-(2-methylbenzylidene)phenylglycine amide (NMPA), which was already studied in a previous paper. On the basis of these outcomes, we conclude by proposing a model-free screening strategy for the design of an effective deracemization process via temperature cycles for a new compound.ISSN:1083-6160ISSN:1520-586