Mechanism of the reaction of epithiochlorohydrin with nucleophiles

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, p. 1424, October, 1988.     

Solid-state reactions of organometallic aldehydes with optically active primary β-hydroxyamines

The solid-state reactions of crystalline ferrocenyl- and ruthenocenylaldehydes with optically active primary β-hydroxyamines were studied at ∼20 °C. The yield of the products increases substantially in the presence of K₂CO₃. The tautomeric equilibrium between imines and diastereomeric oxazolidines with the predominant formation of one of them is established in solutions of the products in CDCl₃. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2240–2243, December, 1997.     

Coherent, two-wave interaction in relativistic Cherenkov generators

A relativistic, two-wave generator working near -type oscillations of two lowest modes with frequency band around 8 mm, is investigated experimentally. Obtained output radiation patterns point to a single-frequency radiation character. The efficiency is found to rise in two-wave regimes in comparison with one-wave ones. The generator assembled of two sections is also considered.     

Electrochemical dissolution of magnetite in acid solutions

The present paper deals with the electrochemical behavior of magnetite microcrystals in an acid medium. A voltammetric method employing a carbon-paste electroactive electrode (CPEE) with an organic binder was used. It was found that the cathodic voltammograms, which were recorded at different scan rates, formed a set bounded in the space of i–E parameters by a generalizing voltammetric curve corresponding to the effective potential scan rate _eff. In other words, all curves are situated under one enveloping curve, just as the smaller dolls sit in the largest doll of a Russian doll. Reverse currents (a cathodic current in the anodic direction of the potential scan) were observed on the cyclic voltammogram. Forward and reverse currents obey the same laws and have one and the same generalizing curve, which could be taken as the magnetite characteristic.     

Research in the isoxazole series

The 4-nitro derivative is formed in the nitration of 3,5-diphenylisoxazole (I) in acetic anhydride. Mononitration of isoxazole I in concentrated H₂SO₄ gave 3-phenyl-5-(p-nitrophenyl)isoxazole, while polynitration gave a mixture of dinitro derivatives, among which 3- (m-nitro-phenyl)-5-(p-nitrophenyl)isoxazole was identified. The structures of the isolated products were established by means of the spectra, by reaction-chromatography methods, and gasliquid chromatography, as well as by a comparison with genuine samples of the two mononitro and four dinitro derivatives of isoxazole I.     

Spin-adducts of η2-metallocomplexes of fullerene-60 with phosphoryl radicals

Using ESR spectroscopy, the reaction of P(O)(OPrⁱ)₂ phosphoryl radicals with C₆₀ML₂ (M=Pd, Pt) was studied and the spin-adducts formed were shown to be unstable under the reaction conditions. The ⁵-addition of Pt(PPh₃)₄ to the dimer of phosphorylfullerenyl radicals results in metal-containing dimers (RO)₂(O)PL₂MC₆₀-C₆₀ML₂P(O)(OR)₂, which dissociate when exposed to visible light to afford C₆₀ML₂P(O)(OR)₂ radicals; ML₂ in these complexes is located in different positions in relation to the radical center. As a result, the ESR spectra contain the superposition of at least five signals of radicals that differ in HFS constants andg-factors.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 938–940, May, 1994.The present work was supported by the Russian Foundation for Basic Research (Projects 93-03-18725 and 93-03-4101).     

Research in the isoxazole series. 38. Polarographic reduction of 4-arylazoisoxazoles

The indicated compounds are reduced on a dropping-mercury electrode in aqueous alcohol solutions at pH > 7 in one two-electron wave to 1,2-disubstituted hydrazines; four-electron reduction with the formation of amines takes place in acidic media. Two one-electron reduction waves are observed in dimethylformamide (DMF). Satisfactory E_1/2– correlation equations were obtained for 4-arylazo-3,5-dimethyloxazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1320–1323, October, 1980.     

Effect of Water Vapor on Chromatographic Characteristics of the Cyclodextrin-Containing Stationary Liquid Phase in Capillary Gas Chromatography

The effects of the presence of water vapor in the carrier gas and the temperature on the retention of achiral and chiral compounds, enantioselectivity, and performance of an open-tubular column with a cyclodextrin-containing phase were studied. The use of a carrier gas containing water vapor in the determination of optically active isomers, such as camphor, slightly increases the retention factor. A substantial improvement of performance characteristics of the column was found: for hydroxy compounds, the column performance increased by two to three times and the peak symmetry improved by more than twice.     

X-ray study of the molecular structure of α-mercury and α-platinummercury derivatives of l-menthyl phenylacetate

The molecular structures of the L-menthyl ester of S-α-bromomercuriphenyl-acetic acid, diastereomer II, [α]²⁰_D ?18°, and of the related L-menthyl ester of α-bromobis(triphenylphosphine)platinummeruriphenylacetic acid, VI, have been investigated by the X-ray method. Insertion of L₂Pt carbenoid appears to occur into the HgBr bond in II and two phosphine ligands in the product VI occupy cis positions in a planar square around the platinum atom. The HgPt distance is 2.50 Å; there is intermolecular HgBr coordination in II, the distance being 3.23 Å.     

Isotope exchange study of the e lectrophilic replacement reaction in a saturated carbon atom

Summary A study of the isotope exchange of the ethyl esters of -brommercuryarylacetic acids with²⁰³Hg Br₂ and 70% aqueous dioxane at 60°, made it possible to arrange the substituents in the following series in order of decreasing reaction rate: p-I, Br, Cl > p-F >H > o-CH₃ > p-CH₃> p-typet. C₄H₉.