Reactions of <Emphasis Type="Italic">Z</Emphasis>-isomers of alkylaromatic 1,2-hydroxylamino oximes with methyl-and arylglyoxals

Reactions of the Z-isomers of alkylaromatic 1,2-hydroxylamino oximes (that contain the hydroxylamino group at the primary or secondary carbon atom) with methylglyoxal gave 6-acetyl-5,6-dihydro-4H-1,2,5-oxadiazines. Analogous reactions with arylglyoxals in the presence of trifluoroacetic acid afforded 6-aroyl-5,6-dihydro-4H-1,2,5-oxadiazines. It was found that phenylglyoxal in the absence of the acid yielded N-substituted α-aroylnitrone which undergoes cyclization into the corresponding oxadiazine under the action of CF₃COOH. Dedicated to the memory of Academician N. N. Vorozhtsov on the 100th anniversary of his birth. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1146–1149, June, 2007.     

Concentration waves in Belousov-Zhabotinsky reactions catalyzed by iron complexes in liquid and viscous media

The concentration dependences of autowave parameters have been established for the Belousov-Zhabotinsky reactions involving Fe(phen) ₃ ²⁺ and Fe(dipy) ₃ ²⁺ as catalysts and malonic or -ketoglutaric acid as a reductant. Plots of autowave parameters against reactant concentration and solution viscosity in such systems containing agar-agar and SiO₂ gel are given.     

Inelastic\bar p p interactions at 22.4 GeV/c compared withe + e − annihilation into hadrons

The 22.4 GeV/c \(\bar p\) p interactions with the leading particle and the slow proton subtracted are used as data on soft processes. Considerable similarity between them and hard processes, such ase ⁺ e ^? annihilation into hadrons, is found by means of studying charged multiplicities, KNO scaling and longitudinal as well as transverse spectra.     

Perturbed stable systems on a plane. Part 1

The possibility of extending the concept of rough dynamical systems in the presence of a time-varying perturbation defined up to a functional set in the space of piecewise continuous functions is considered. The constructability of this extension is achieved by the construction of limit cycles giving an estimate of attainability sets for oscillatory systems.     

Coordination chemistry of anticrowns. An unusual complex of perfluorinated three-mercury anticrown (o-C6F4Hg)3 with p-bromotoluene and 1,2-dichloroethane

Russian Chemical Bulletin -     

Coordination chemistry of anticrowns. Complexation of cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4Hg)3 with compounds containing an active methylene group

The reactions of three-mercury anticrown (o-C₆F₄Hg)₃ (1) with acetoacetic ester (AE), malonic ester (ME), and malonodinitrile (MN) afford 1: 1 complexes {[(o-C₆F₄Hg)₃](AE)} (3), {[(o-C₆F₄Hg)₃](ME)} (4), and {[(o-C₆F₄Hg)₃](MN)} (5). The structures of complexes 3–5 were determined by X-ray diffraction analysis. Complex 3 has a discrete structure in the solid state, whereas complexes 4 and 5 form in the crystal extended stacks representing polydecker sandwiches with alternating molecules of 1 and ME or MN. According to the X-ray diffraction and IR spectral data, the molecule of AE in complex 3 is in the keto form.     

Effect of molecular oxygen on concentration autooscillations and autowaves in the Belousov-Zhabotinskii reaction

It has been established that molecular oxygen is responsible for the differences in the concentration regions for existence of autooscillations and autowaves in the Belousov-Zhabotinskii reaction when the reaction mixture is in contact with air. When gaseous oxygen is passed through the solution, it affects the oscillation parameters through two mechanisms: chemical interaction with malonic acid radicals, and removal of free bromine from the solution. The influence of stirring intensity on the autooscillation parameters in Belousov-Zhabotinskii reactions is related mainly to changes in the rate of access of molecular oxygen to the reaction mixture.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 24, No. 6, pp. 661–666, November–December, 1988.     

Crown compounds for anions. Sandwich complexes of cyclic trimeric perfluoro-o-phenylenemercury with hexacyanoferrate(III) and nitroprusside anions

Cyclic trimeric perfluoro-o-phenylenemercury (o-C₆F₄Hg)₃ (1) is able to bind hexacyanoferrate(III) and nitroprusside anions to form complexes {[(o-C₆F₄Hg)₃]₂[Fe(CN)₆]}³⁻ and {[(o-C₆F₄Hg)₃]₂[Fe(CN)₅NO]}²⁻, respectively, which contain one anionic species per two macrocycles. According to X-ray diffraction data, the complexes have unusual sandwich structures wherein the anionic guest is located between the planes of two molecules of 1 and is coordinated to each of these through two types of Fe-C-N-Hg bridges. One type is the simultaneous coordination of a cyanide ligand to all three Hg centres of the cycle. The other type is the coordination of a cyanide group to a single Hg atom of the macrocycle. In both types, the bonding of the anionic guest with the macrocyclic host is accomplished with the participation of π-electrons of the cyanide ligands. The synthesized compounds are the first examples of host-guest complexes of a macrocyclic multidentate Lewis acid with anionic metal complexes.     

Polarographic oxidation of triarylimidazoles

Ten series of triarylimidazoles were subjected to polarographic oxidation. It was found that electron-donor substituents facilitate polarographic oxidation, while electron-acceptor substituents hinder it. Correlation equations in coordinates of E_1/2 and ⁺ were found for all of the investigated series.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 387–390, March, 1973.The synthesis and characteristics of the investigated imidazoles were described in [7–10].     

Stabilization of circular states of the hydrogen atom in a strong field

A solution of the three-dimensional time-dependent Schrödinger equation, describing the ionization dynamics of the hydrogen atom in a circular state in an electromagnetic field, is obtained by direct numerical integration. It is shown that the observed stabilization effect can be interpreted on the basis of the Kramers-Henneberger approach. A simple analytical model is proposed, which qualitatively describes the basic laws of the ionization process under the conditions of the reported calculations and laboratory experiments on ionization of the circular hydrogenlike 5g, m=4 state of the Ne atom.