The magnetocaloric effect (MCE) is calculated in the framework of the Landau theory in a as a solid refrigerant. Exchange fields arise at the interfaces suppressing antiferromagnetic order in the interlayer which leads to an increase in its entropy. The direction of these exchange fields (the direction of magnetizations of the FM layers) can be changed by variation of an external magnetic field. The isothermal entropy change caused by a change in this direction from perpendicular to parallel relative to the easy axis of the AFM interlayer can reach up to 5 x 105 erg K-1 cm-3 (13 J kg-1 K-1) in the FM/MnF2/FM structure if the field of 10 kOe is applied. Large exchange enhancement of the MCE in this layered structure is demonstrated compared to a separate MnF2 layer. The obtained results may be useful in thin-film coolers.

Distally substituted bis-1,3-diketone derivatives of calix[4]arene were synthesized, in which chelate groups are attached via a carbonyl carbon atom to the p-positions of phenolic fragments of a macrocycle fixed in 1,3-alternate isomeric form. 1,3-Diketone derivatives were obtained by acylation of magnesium enolate of a calix[4]arene ketone with 1-benzoylbenzotriazoles. In the synthesized compounds, 1,3-diketone groups are conjugated with the π-aromatic system of calix[4]arene. It was found by means of UV spectroscopy and NMR diffusion methods in combination with quantum chemical (DFT) calculations that a mononuclear complex with bis-chelate coordination of the lanthanide ion is predominantly formed in the solution. The formation of the complex leads to a decrease in the conjugation degree in the ligand. The most effective sensitization of Eu3+ luminescence, compared to the p-F- or p-CF3-phenyl-substituted complexes is observed for calix[4]arene complexes with H-phenyl-substituted 1,3-diketone groups.

The reaction pathway of the interaction of curcumin molecule with HO2 radicals has been studied at the density functional theory level using the hybrid PBE0 functional. In order to study the reaction mechanism, transition states were found by a special optimization procedure, which were then checked for compliance with the reaction under study by the procedure of following the internal reaction coordinate IRC. All found transition states corresponded to the reaction under study. Using descent from the transition state structure, the structures of the pre- and post-reaction complexes were determined, which made it possible to determine the activation energy of the reaction. It is shown that this reaction is characterized by a noticeable thermodynamic probability (significantly negative G0 value). This means that when the chemical equilibrium of the reaction is reached, an appreciable amount of the radical quenching product, which is hydrogen peroxide Н2О2, will accumulate in the system. This fact indicates the antioxidant activity of curcumin molecules, although it cannot be concluded from the activation characteristics of the reaction that this reaction is rapid. The interaction of curcumin in aqueous solution with Cu(II) ion leads to the formation of a chelate complex, which exhibits slightly more marked antioxidant activity towards HO2 radicals compared to free curcumin molecules. This is explained by the more negative values of the Gibbs free energy of the curcumin reaction within the complex. From the point of view of reaction kinetics, complexation does not lead to noticeable differences in the values of enthalpy of activation H and Gibbs free energy of activation G

In this work, the structures of an inclusion compound and an adduct based on quercetin and cucurbit[7]uril are obtained using the density functional theory with the PBE functional and the Alrich Def2-TZVP atomic basis set for all atoms. The aim of the work was to find out whether it is possible to use CB[7] as a molecular "container" for the antioxidant quercetin for targeted delivery to a given area of the body, organ or cell. It is shown that fully gas-phase calculations, calculations in the molecular model and in a more rigorous combined molecular-continuum model give significantly different quantitative results for the thermodynamic characteristics of the processes of adduct and inclusion compound formation. At the same time, the results obtained in the combined model convincingly demonstrate the thermodynamic possibility of forming these structures in an aqueous solution. The formation of supramolecular compounds occurs due to the formation of many weak bonds, among which dispersion interactions can play a significant role. Therefore, at the last stage of calculations, dispersion interactions were taken into account within the framework of the semi-empirical Grimme D4 model. Such calculations showed that taking into account dispersion interactions in the considered systems has little effect on ΔGo298 of adduct formation, while for the inclusion compound its thermodynamic probability of formation becomes more noticeable.

This study carried out a detailed step-by-step PBE/TZVP level analysis of the inclusion of Fe(III)/Fe(II) aqua complexes into the cavity of cucurbit[6]urils (CB[6]). The structural characteristics of all intermediate stable structures formed during the inclusion process from the bulk of aqueous solution to the inclusion compound were obtained. To account for solvation effects, a molecular-continual model was used in which six water molecules of the first coordination sphere of aqua complexes and 12 water molecules of the second coordination sphere were taken into account, while the interaction of such a supermolecule with a dielectric medium was accounted within the continuum model (PCM). The process of incorporation of the aqua complex into the cavity was found to be accompanied by a partial desolvation of the second coordination sphere of the aqua complex and a change in the structure of the first coordination sphere. Additionally, the standard electrode potential of the half-reaction Fe-(aq)(3+) + e = Fe-(aq)(2+) was estimated for all adducts formed in the reaction.

The regularities of chromatographic retention and separation enantioselectivity of the selected β-blockers (propranolol, pindolol, alprenolol, atenolol, oxprenalol, metoprolol, clenbuterol, sotalol, pronethalol, salbutamol, and labetalol) were studied with eight chiral stationary phases (CSPs) in polar ionic mode (PIM) elution system. A range of novel CSPs was prepared by immobilisation of macrocyclic glycopeptide antibiotic eremomycin (E-CSP); structurally related antibiotics chloreremomycin (Chloro-E-CSP) and semi-synthetic oritavancin (O-CSP); and five eremomycin derivatives including amide- (Amide-E-CSP), adamantyl-2-amide- (Adamantylamide-E-CSP), eremomycin aglycon (EAg-CSP), eremosaminyl eremomycin aglycon (EEA-CSP), and des-eremosamynyl eremomycin (DEE-CSP) onto microspherical silica (Kromasil, particle size 5 micron, pore size 11 nm). The effect of different functional groups in eremomycin structure on chiral recognition of β-blockers was studied. The original E-CSP revealed moderate enantioseparation for all studied β-blockers. The presence of a free carboxylic group in a chiral selector molecule is found to be critical for the general retention of enantiomers as no separation enantioselectivity was recorded for Amide-E-CSP and Adamantyl-E-CSP. Modification of the aromatic system of eremomycin by the introduction of a chloro- substituent in the aromatic ring (Chloro-E-CSP) or a hydrophobic 4’-chlorobiphenylmethyl substituent to the disaccharide sugar residue (O-CSP) resulted in decreased enantioselectivity. The best enantioseparation of β-blockers was obtained for CSPs with eremosaminyl eremomycin aglycon and des-eremosamynyl eremomycin as chiral selectors.

Bromination of 4,4,6-trimethyl-4H-pyrrolo[3,2,1-ij]quinoline-1,2-diones containing an allylic moiety with N-bromosuccinimide (NBS) in carbon tetrachloride in the presence of benzoyl peroxide (BPO) and in DMF solution were studied. When using an equimolar amount of NBS in the BPO-CCl4 system, the reaction proceeds regioselectively and standardly at the methyl group at position 6 with the formation of 6-bromomethylene derivatives. In the NBS-DMF system, monobromination proceeds at position 5 with the migration of a multiple bond by the allylic rearrangement. With a twofold excess of NBS, in both cases a (Z)-5-bromo-6-bromomethylene derivative is formed. The 5-monobromine isomers undergo retro-allylic rearrangement in N- and S-alkylation reactions, resulting exclusively in 6-N-alkyl and 6-S-alkyl derivatives, respectively. Similar products are formed by the same reactions with the use of 6-bromomethylene derivatives.

It is shown that the energy of a ferromagnetic film deposited onto a paramagnetic or superconducting substrate acquires a contribution in the form of the Dzyaloshinskii–Moriya interaction. This contribution appears as a result of the magnetostatic interaction of the magnetization of the ferromagnetic film with the magnetization induced by it in a paramagnet or by the supercurrent in the superconductor and leads to the removal of the chiral degeneracy, nonreciprocity of spin waves, and the formation of chiral states such as magnetic skyrmions. Our estimates indicate the possibility of experimental observation of predicted effects.

It is shown that a term in the form of Dzyaloshinskii-Moriya interaction (DMI) contributes to the free energy of a ferromagnetic (FM) film on a paramagnetic (PM) (an FM above the critical temperature, Tc) or superconducting (SC) substrate occurring in the London limit. This contribution results from magnetostatic interaction between the film and substrate under which the substrate affects FM magnetization back via its magnetic field produced by magnetization inhomogeneity in the film. Strikingly, in the FM/PM system this effective DMI stabilizes chiral magnetic textures, e.g., magnetic skyrmions (MSk's) of the Neel-type, which is in contrast to that in the FM/SC one. A strong temperature sensitivity of the effective DMI allows for tuning the coupling between the FM film and PM or SC substrate and thus controlling the MSk radius in FM/PM.

Unsubstituted and 1-methyl-substituted 1,3,4,8b-tetrahydrodiazirino[3,1-a]isoquinolines (diaziridines 1 and 2) demonstrate different reactivities toward aryl isocyanates and aryl isothiocyanates. Diaziridine 1 reacts with aryl isocyanates as a nucleophile to afford novel 1,5,6,10b-tetrahydro[1,2,4]triazolo[5,1-a]isoquinolines. The addition of a Lewis or Bronsted acid switches the reaction pathway, producing seven-membered 2,3-benzodiazepines. In reactions of diaziridine 1 with aryl isothiocyanates, unusual zwitterionic compounds - 2-thioxo-5,6-dihydro-2H-[1,2,4]triazolo[5,1-a]isoquinolin-1-ium-3-ides - and products of the addition of two molecules of diaziridine 1 to one molecule of aryl isothiocyanate are obtained. However, in reactions with aryl iso(thio)cyanates under heating or acid catalysis, diaziridine 2 is first converted into an azomethine imine, the 1,3-dipolar cycloaddition of which to the dipolarophile produces substituted triazolo[5,1-a]isoquinolin-2(3H)-(thi)ones. Proposed is a new method for azomethine imine generation from diaziridine 2 enabled by Bronsted acid catalysis. Antitumour activity of select compounds obtained was assayed to help guide future drug discovery efforts.

The review considers the main results of the cycloaddition reactions involving cyclopropenes and methylenecyclopropanes, the compounds bearing strained three-membered rings and, respectively, endo- and exocyclic double bonds. The main attention is focused on the reactions of these compounds with 1,3-dipoles (nitrones, azomethine imines, azomethine ylides, carbonyl ylides, etc.), which gave complex heterocyclic systems with high regio- and stereoselectivity.

Selectivity of nitrene addition to the CCS fragment depends on the oxidative state of the sulfur atom as has been exemplified on various derivatives of 3,4-dihydro-2H-thiopyran under conditions of oxidative aminoaziridination. A unique structure with 2-thia-7-azabicyclo[4.1.0]heptane-2,2-dioxide core was obtained via addition of nitrene to the CC bond of thiopyran S,S-dioxide. For an unoxidized thiopyran, only en(phthaloyl)hydrazine resulted after cleavage of the initially formed aziridine. S-Oxide trapped the nitrene by the sulfur atom to form the sulfoximine leaving the double bond unaffected.

Spin-wave (SW) spectra have theoretically been studied in a thin film of a ferromagnet (FM) on a substrate from a paramagnet (PM) (an FM above the critical temperature) or from superconductor (SC). A spin-wave propagating in the FM induces the dynamic magnetization and superconducting current in the underlying PM and SC, respectively, which affect the SW propagation by their magnetic fields. As a result of this interaction, the SW spectrum becomes nonreciprocal to depend on the sign of the SW wave-vector q. We show that the nonreciprocal contribution to the SW spectra in FM/PM and FM/SC systems is given by the frequency shift of Delta omega(q) (math) omega(q)-omega(-q) = a(T)(tau.q) with tau = (n x M) being the toroidal magnetic moment, M the FM magnetization, n the unit vector normal to the FM/PM(SC) interface, and a(T) the temperature-dependent constant of a dipole nature, whose sign depends on the substrate type. As the Delta omega(T) dependence is strong at temperatures T close to the critical temperature T-c for the FM-PM or normal metal-SC transition, one gets a possibility to control the frequency SW nonreciprocity with temperature variation near T-c. The dipolar mechanism we propose for SW frequency nonreciprocity is promising for introducing this property of SW propagation into functional devices.

An effective approach to access functionalized 2H-cyclonona(deca)[d]isoxazoles and 15-oxo-3,10-methanobenzo[b][1]azacyclododecines has been developed by the reaction of N-aryl-C,C-bis(methoxycarbonyl)nitrones with cyclonona(deca)-1,2-dienes in a one-pot fashion. The reaction of N-aryl-C-(phenylcarbamoyl)nitrones with these allenes proceeds strictly regioselectively giving the mixtures of diastereomeric isoxazolidines containing a double bond at the C4-position of the isoxazolidine ring. The quantum chemical calculations show that the regioselectivity of these reactions is in good agreement with the reactivity indices of the considered compounds.

Магнитокалорический эффект (МКЭ) заключается в изменении температуры образца при приложении внешнего магнитного поля. Классическим примером МКЭ является охлаждение парамагнитных солей до сверхнизких (10−2−10−3 K) температур при их адиабатическом размагничивании [1]. В последние годы интерес к МКЭ связан с возможностью создания “магнитных холодильников” на основе сплавов гадолиния, работающих при комнатной температуре [2, 3]. Эффективность адиабатического магнитного охлаждения характеризуется отношением dT/dH изменения температуры образца к изменению магнитного поля. Достигнутые к настоящему времени значения эффективности охлаждения при адиабатическом размагничивании в однородном внешнем поле не превышают 10 град./Тл [4]. Целью данной работы является исследование магнитокалорического эффекта в магнитных многослойных структурах, для которых намагничивание (или размагничивание) определяется эффектом “близости”, связанным с обменным взаимодействием различных магнитных слоев. Мы покажем, что эффективность магнитного охлаждения в этих системах может достигать предельного значения в однородных системах, или даже превышать его [4]. Отметим, что изучение особенностей МКЭ в наноструктурах вызывает возрастающий интерес [5, 6]. Рассмотрим многослойную структуру F/f/F, где под F понимается “сильный” ферромагнетик, температура Кюри которого выше температуры образца (TF > T ), а под f – прослойка “слабого” ферромагнетика, для которого температура Кюри Tf < TF. Тем-

Ketonitrones containing two ester groups react regio- and stereoselectively with 1,3-diarylpropenones to form isoxazolidines with ester groups at position 3 of the ring. The action of zinc in acetic acid on these isoxazolidines causes opening of the ring with the formation of 3-amino alcohols, the subsequent cyclization of which leads to polysubstituted lactones. Reduction of the benzoyl group of isoxazolidine with sodium borohydride leads, as a result of subsequent transformations, to the formation of substituted 1,3,4-triaryl-6-oxodihydro-1H,3H-furo[3,4-c]isoxazole-6a(6H)-carboxylates as single diastereomers.

The first example of the cycloaddition of in situ-generated azomethine imine under microwave conditions is described. The reaction of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes with 1,3-diphenylprop-2-en-1-ones proceeds regio- and stereoselectively giving mostly good yields of the corresponding perhydropyrazolopyrazoles. The products of the reaction undergo cycloreversion under the reaction conditions.

In the article the basic problems of state regulation of reproduction relations of economy are considered, Statue Concerning state regulation of balance in innovative structure of economy is proved.