Single Impurity In Ultracold Fermi Superfluids

The role of impurities as experimental probes in the detection of quantum material properties is well appreciated. Here we study the effect of a single classical magnetic impurity in trapped ultracold Fermi superfluids. Depending on its shape and strength, a magnetic impurity can induce single or multiple mid-gap bound states in a superfluid Fermi gas. The multiple mid-gap states could coincide with the development of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase within the superfluid. As an analog of the Scanning Tunneling Microscope, we propose a modified RF spectroscopic method to measure the local density of states which can be employed to detect these states and other quantum phases of cold atoms. A key result of our self consistent Bogoliubov-de Gennes calculations is that a magnetic impurity can controllably induce an FFLO state at currently accessible experimental parameters.Comment: 5 pages, 3 figures; added calculations for 3

Stable σh-adducts in the reactions of the acridinium cation with heterocyclic N-nucleophiles

A reaction of NH-heterocycles with the 10-methylacridinium cation in the presence of a base led to 9,10-dihydro-10-methyl-9-substituted acridines, which can be considered as stable intermediates in the aromatic nucleophilic substitution reaction of hydrogen. The structure of the intermediates was studied and their oxidation potentials were determined. Generally, the oxidation potential was found to symbatically change with the changes in the energy of HOMO. © 2013 Springer Science+Business Media New York

A rational protocol for the synthesis of 1-(2-pyridyl)isoquinolines

Aza-Diels-Alder reaction between 3-(2-pyridyl)-1,2,4-triazines and 1-morpholinocyclohexene followed by aromatization of the cyclohexene moiety affords 1-(2-pyridyl)isoquinolines. Crystal structures of two tetrahydroisoquinolines were confirmed by X-ray diffraction analysis. © 2013 Mendeleev Communications. All rights reserved

Development of Drugs with Direct Antiviral Action Based on Azaheterocyclic Systems

Abstract: This article discusses the results of studies carried out in recent years by a team of scientists from the Postovskii Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, in cooperation with the First President of Russia Boris Yeltsin Ural Federal University, Ural State Medical University, Volgograd State Medical University, and other scientific and production organizations of the country to create triazavirin (riamilovir) and other direct etiotropic antiviral drugs based on azaheterocyclic derivatives. © 2022, Pleiades Publishing, Ltd.National Natural Science Foundation of China, NSFC, (20-53-55003)Russian Foundation for Basic Research, РФФИThis work was supported by the Russian Foundation for Basic Research and the National Natural Science Foundation of China within research project no. 20-53-55003

Dibenzo[ f,h]furazano[3,4- b]quinoxalines: Synthesis by Intramolecular Cyclization through Direct Transition Metal-Free C-H Functionalization and Electrochemical, Photophysical, and Charge Mobility Characterization

Herein, we describe the synthesis of unsymmetrically substituted dibenzo[f,h]furazano[3,4-b]quinoxalines by intramolecular cyclization through direct transition metal-free C-H functionalization. The electrochemical and photophysical properties for several polycycles have been measured. In thin films of the dibenzo[f,h]furazano[3,4-b]quinoxalines, hole mobility is in the order of 10-4 cm2 V-1 s-1. The results show that the HOMO and LUMO energy levels are appropriate for using the compounds as hole-transport materials in thin-film devices, in particular, organic and perovskite solar cells. Copyright © 2020 American Chemical Society.Russian Foundation for Basic Research, RFBR: 18-33-00103-mol_aRussian Science Foundation, RSF: 18-13-00409The research was financially supported by the Russian Science Foundation (project no. 18-13-00409). Y.A.K would like to acknowledge the financial support for the part of the synthetic section from the Russian Foundation for Basic Research (research project no. 18-33-00103-mol_a). The authors are grateful to Grigory A. Kim for carrying out the DFT calculations, which were performed by using “Uran” supercomputer of the Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences. NMR experiments were carried out by using equipment of the Center for Joint Use “Spectroscopy and Analysis of Organic Compounds” at the Postovsky Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences

Benzyne-mediated rearrangement of 3-(2-pyridyl)-1,2,4-triazines into 10-(1H-1,2,3-triazol-1-yl)pyrido[1,2-a]indoles

The reaction between 5-R-6-R1-3-(2-pyridyl)-1,2,4-triazines and benzyne generated in situ in toluene under reflux results in the formation of 10-(1H-1,2,3-triazol-1-yl)pyrido[1,2-a]indoles 3 in up to 60% yields instead of the expected 3-R-4-R1-1-(2-pyridyl)isoquinolines 2. The crystal structure of product 3c and the proposed mechanism for the formation of 3 are reported. © 2013 Elsevier Ltd. All rights reserved

Microwave-assisted palladium-catalyzed C-C coupling versus nucleophilic aromatic substitution of hydrogen (SN H) in 5-bromopyrimidine by action of bithiophene and its analogues

5-Bromopyrimidine reacts with 2,2′-bithiophene, [2,2′:5′, 2″]terthiophene and 2-phenylthiophene in the presence of a palladium catalyst to give 5-(het)aryl substituted pyrimidines due to the palladium-catalyzed aryl-aryl C-C coupling. However 5-bromo-4-(het)aryl- pyrimidines have been prepared from the same starting materials through the SN H-reaction catalyzed by a Lewis acid. Conditions for both types of reactions were optimized. All components of the reaction mixtures, including by-products, have been elucidated by gas-liquid chromatography/mass- spectrometry. Evidence for the structure of 4- and 5-bithiophenyl-substituted pyrimidines has first been obtained by means of X-ray crystallography analysis. Molecular orbital calculations (TDDFT), as well as the redox and optical measurements for all new compounds have also been performed. © 2013 Elsevier Ltd. All rights reserved

Distinguishing d-wave from highly anisotropic s-wave superconductors

Systematic impurity doping in the Cu-O plane of the hole-doped cuprate superconductors may allow one to decide between unconvention al ("d-wave") and anisotropic conventional ("s-wave") states as possible candidates for the order parameter in these materials. We show that potential scattering of any strength always increases the gap minima of such s-wave states, leading to activated behavior in temperature with characteristic impurity concentration dependence in observable quantities such as the penetration depth. A magnetic component to the scattering may destroy the energy gap and give rise to conventional gapless behavior, or lead to a nonmonotonic dependence of the gap on impurity concentration. We discuss how experiments constrain this analysis.Comment: 5 page

Local Electronic Structure of a Single Magnetic Impurity in a Superconductor

The electronic structure near a single classical magnetic impurity in a superconductor is determined using a fully self-consistent Koster-Slater algorithm. Localized excited states are found within the energy gap which are half electron and half hole. Within a jellium model we find the new result that the spatial structure of the positive-frequency (electron-like) spectral weight (or local density of states), can differ strongly from that of the negative frequency (hole-like) spectral weight. The effect of the impurity on the continuum states above the energy gap is calculated with good spectral resolution for the first time. This is also the first three-dimensional self-consistent calculation for a strong magnetic impurity potential.Comment: 13 pages, RevTex, change in heuristic picture, no change in numerical result

Direct synthesis of 5-arylethynyl-1,2,4-triazines via direct CH-functionalization

An efficient synthetic approach towards 5-arylethynyl-1,2,4-triazines via direct C-H-functionalization of 5-H-1,2,4-triazines in reaction with lithium acetylenes is reported