Synthesis of Bis‐ and Tris(3‐H‐1,3‐azaphospholo)benzenes

The previously developed intramolecular cyclocondensation of C‐phosphanyl(N‐aryl)formamidines into 3‐H‐1,3‐benzazaphospholes has been successfully extended to 1,3‐diaminobenzene and 1,3,5‐triaminobenzene. Its condensation presents the way to tricyclic and tetracyclic azaphospholes. Their structures were confirmed by spectroscopic methods and key tricyclic and tetracyclic compounds were further characterized by single crystal X‐ray diffraction.     

Spatial confinement of ferromagnetic resonances in honeycomb antidot lattices

We report on a theoretical investigation of the magnetic static and dynamic properties of a thin ferromagnetic film with honeycomb lattice of circular antidots using micromagnetic simulations and analytical calculations. The theoretical model is based on the Landau–Lifshitz equations and directly accounts for the effects of the magnetic state nonuniformity. A direct calculation of local dynamic susceptibility tensor yields that the resonance spectra consist of four different quasi-uniform modes of the magnetization precession related to the confinement of magnetic domains by the hole mesh. Three of four resonant modes follow a two-fold variation with respect to the in-plane orientation of the applied magnetic field. The easy axes of these modes are mutually rotated by 60° and combine to yield the apparent six-fold configurational anisotropy. Additionally, a mode with intrinsic six-fold symmetry behavior exists, as well. Micromagnetic calculations of the local dynamic susceptibility tensor allow identifying the magnetic unit cell areas/domains responsible for each resonance mode.     

Synthesis and magnetic relaxation properties of a porous glass magnetic microcarrier

The reaction of formation of magnetic iron oxide nanoparticles from aqueous solutions of Fe(+2,+3) salts was studied under homo- and heterophase conditions of capillary-porous bodies by the nuclear magnetic resonance relaxometry method. Magnetic composites based on Bio-Glas porous glasses were obtained by precipitation of iron oxide nanoparticles in pores ranging in size from 50 to 250 nm. The magnetic relaxation rate of water protons during the heterophase precipitation reaction was examined.     

Synthesis, X-Ray Diffraction Data, and 1H and 13C NMR Spectra of N-(N-Arylsulfonylimidoyl)-1,4-benzoquinonimines Derived from N-Aroyl(acetyl)-1,4-benzoquinonimines

Oxidation of N-(N-arylsulfonylimidoyl)-4-aminophenols gave the corresponding N-[N-arylsulfonylimidoyl)-1,4-benzoquinonimines, derivatives of N-aroyl- and N-acetyl-1,4-benzoquinonimines. The structure of the products was studied by the X-ray diffraction method and ¹H and ¹³C NMR spectroscopy. N-(N-Arylsulfonylimidoyl)-1,4-benzoquinonimines were found to undergo fast (on the NMR time scale) Z E isomerization about the CÍN bond in the quinonimine fragment. N-(N-Arylsulfonylacetimidoyl)-1,4-benzoquinonimines in solution give rise to dynamic Z E-isomerization with respect to the CÍN bond in the N-arylsulfonylacetimidoyl fragment.     

Rational Screening of High-Voltage Electrolytes and Additives for Use in LiNi0.5Mn1.5O4-Based Li-Ion Batteries

In the present work, we focus onthe experimental screening of selected electrolytes, which have been reported earlier in different works, as a good choice for high-voltage Li-ion batteries. Twenty-four solutions were studied by means of their high-voltage stability in lithium half-cells with idle electrode (C+PVDF) and the LiNi_0.5Mn_1.5O₄-based composite as a positive electrode. Some of the solutions were based on the standard 1 M LiPF₆ in EC:DMC:DEC = 1:1:1 with/without additives, such as fluoroethylene carbonate, lithium bis(oxalate) borate and lithium difluoro(oxalate)borate. More concentrated solutions of LiPF₆ in EC:DMC:DEC = 1:1:1 were also studied. In addition, the solutions of LiBF₄ and LiPF₆ in various solvents, such as sulfolane, adiponitrile and tris(trimethylsilyl) phosphate, atdifferent concentrations were investigated. A complex study, including cyclic voltammetry, galvanostatic cycling, impedance spectroscopy and ex situ PXRD and EDX, was applied for the first time to such a wide range of electrolytesto provide an objective assessment of the stability of the systems under study. We observed a better anodic stability, including a slower capacity fading during the cycling and lower charge transfer resistance, for the concentrated electrolytes and sulfolane-based solutions. Among the studied electrolytes, the concentrated LiPF₆ in EC:DEC:DMC = 1:1:1 performed the best, since it provided both low SEI resistance and stability of the LiNi_0.5Mn_1.5O₄ cathode material.     

Incorporation of Naphthalocyanine into Shells of Polyelectrolyte Capsules and Their Disruption under Laser Radiation

Different methods have been proposed for the incorporation of a dye, vanadyl tetra-5,14,23,32-phenyl-2,3-naphthalocyanine, into the shells of polyelectrolyte capsules. Capsule preparation conditions have been selected to provide efficient incorporation of the dye and stability of capsules to aggregation. A suspension of the capsules has been irradiated with lasers operating at wavelengths belonging to the near-infrared spectral region. It has been found that the capsules can be disrupted under the irradiation. Continuous and pulsed laser radiations have been shown to have different effects on the capsules.     

Temperature-Abnormal Diffusivity in Tilted Periodic Potentials

JETP Letters - The diffusion of particles in tilted spatially periodic potentials in systems with different friction coefficients γ' has been studied in a wide temperature range. It has...     

On a new type of sublattice tipping in noncollinear antiferromagnets

An explanation is offered for the 30° tipping of sublattices which has been observed in the noncollinear antiferromagnet CsMnI₃. In contrast to the ordinary 90° spin flop, this phase transition is due to nonlinear and relativistic corrections to the susceptibility. Pis’ma Zh. éksp. Teor. Fiz. 68, No. 11, 844–846 (10 December 1998)