Measuring the Electric Field Strength of Microwave Radiation at the Frequency of the Radiation Transition Between Rydberg States of Atoms 85Rb

Optics and Spectroscopy - The spectral characteristics of the resonance effect of the electromagnetic-induced transparency (EIT) of rubidium atomic vapors induced by intense radiation with a...     

Novel aurophilic organic ligands based on 1,3-dibromo-propan-2-ol and 2-aminothiophenol

The nucleophilic substitution reactions in 1,3-dibromo-propan-2-ol and the products of its acylation under the action of 2-aminothiophenol were investigated. It was shown that the resulting derivatives containing nitrogen and sulfur donor atoms form coordination compounds in the reactions with copper(II) salts. The possibility of chemosorption of the obtained ligands and complexes containing additional disulfide fragments on the gold electrode surface with the formation of an Au-S bond was demonstrated.     

Synthesis of substituted 5-diethoxymethyl-5-ethyloxazolidines

Mixtures of stereoisomeric 2-diethoxymethyl-5-ethyloxazolidines with one of the stereoisomeric forms predominating were obtained by the reaction of 2-ethyl-2-formyloxirane diethyl acetal with alkyl-substituted Schiff bases in ethanol solution.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, 985–988, July, 1987.     

Purification of the specific immunoglobulin G1 by immobilized metal ion affinity chromatography using nickel complexes of chelating porous and nonporous polymeric sorbents based on poly(methacrylic esters). Effect of polymer structure

Ni2+ complexes of the chelating nonporous and porous bead sorbents based on methacrylic esters crosslinked with ethylene dimethacrylate were used in isolation of the horseradish peroxidase-specific immunoglobulin IgG1 from the crude mouse ascitic fluid by immobilized metal ion affinity chromatography (IMAC). Iminodiacetic and aspartic acids were attached to porous poly(glycidyl methacrylate) beads differing in size, morphology and chemical composition. Ethylenediaminetriacetic acid and quinolin-8-ol chelating groups were attached mainly to the surface hydroxyl groups in nonporous poly(diethylene glycol methacrylate) beads through spacers. The latter sorbents exhibited better kinetic characteristics than the former but a very low IgG1 sorption capacity. In a single-step IMAC procedure, the best efficiency in the specific IgG1 purification was obtained with porous sorbents (recovery 92%, purity 73%). Differences in IMAC separations are discussed from the point of view of morphology of polymer beads as well as of the type and concentration of chelating ligands.     

Quantum-Chemical Investigation of the Mechanism of Transfer of Fluorine in the Reaction of F‐TEDA‐BF4 with Dimethylenebicyclo[3.3.1]nonane

The mechanism of the reaction of the N-fluoro reagent FTEDABF₄ with dimethylenebicyclo[3.3.1]nonane was investigated by the semiempirical PM3 SCF MO method using the Cramer–Truhlar SM5.42R solvation model. It was shown that the mechanism of addition of the fluorine corresponds to classical S _N 2 nucleophilic substitution involving single-electron transfer synchronous with the cleavage–formation of C—F and N—F bonds.     

Reaction of acetyloxiranes with acetonitrile

2-Acetyloxiranes react with acetonitrile in the presence of equimolar amounts of Lewis acids. It was established that the use of boron trifluoride etherate or sulfuric acid as the catalyst leads to 2,7- and 3,6-diepoxy-1,5-dioxocanes, the use of aluminum trichloride, as well as stannic chloride, leads to the corresponding chlorohydrins, while the use of gaseous boron trifluoride leads to 2-oxazolines in satisfactory yields. It is shown that the reaction is regio- and stereospecific and that the resulting substituted 2-methyl-5-acetyl-2-oxazolines have a cis configuration.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No, 8, pp. 1022–1024, August, 1982.     

Molecular and crystal structure of tetrahydroneosophoramine

The structure of tetrahydroneosophoramine has been studied by x-ray structural analysis. Rings A, B, and C have the chair conformation, and ring D the half-chair conformation. On the basis of a semiquantitative analysis it has been shown that the strains in the molecules of tetrahydroneosophoramine and of matrine are of the same order of magnitude.Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Crystallography, Academy of Sciences of the USSR, Moscow. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 751–757, November–December, 1981.     

Adaptive classification method and measurement of intermittent random process characteristics

Results are presented of an analytic construction and investigation of adaptive data classification algorithms for intermittent turbulence. A decision making rule is presented, relationships are derived to estimate the classification accuracy. A three-level procedure is described for processing the intermittency, including the calculation algorithms for the initial point, self-teaching, and optimal classification. It is shown that the method proposed permits realization of total automation of intermittency data processing.Translated from Teoreticheskaya i Prikladnaya Mekhanika, No. 18, pp. 119–123, 1987.     

On the concentration dependence of the sensitized phosphorescence quantum yield of naphthalene in toluene at 77 K

A concentration dependence of the sensitized phosphorescence quantum yield of naphthalene (with benzophenone as a donor) in equimolar toluene solutions at 77 K is studied for concentrations of components ranging from 0.1 to 0.5 mole/litre. A nonmonotonic character of this dependence is established. With increasing solution concentration, intervals of increase (from 0.1 to 0.35) and decrease (from 0.35 to 0.5) of the sensitized phosphorescence quantum yield are observed. Reasons for this dependence are discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 3–6, October, 2004.     

Structure of a new crystalline modification of 4-amino-5-ethoxymethyl-1,2-dimethylpyrimidinium iodide

The structure of a new crystalline modification (II) of 4-amino-5-ethoxymethyl-1,2-dimethylpyrimidinium iodide, C₉H₁₆IN₃O, the major product of methylation of 4-amino-5-ethoxymethyl-2-methylpyrimidine has been determined. The lattice parameters are a = 6.528(4) Å, b = 15.325(7) Å, c = 12.653(6) Å, γ = 97.57(50)°, sp. gr. P2₁/b, Z = 4, R = 0.0348 (over 1480 independent reflections). The molecule is planar. Its pyrimidine ring has the 2,5-diene structure and shows a weak tendency to adopt the C(2)-sofa conformation. Molecules in the crystal structure are linked into centrosymmetric dimers by N(8)-H?N(3) hydrogen bonds. These dimers, in turn, are linked into a three-dimensional framework by I^?-ions. The structure of modification II is compared with the structures of other 4-aminopyrimidines.