Showing papers in "Russian Chemical Bulletin in 1983"
TL;DR: In this article, the relation of the rate of reaction of O/sub 3/ with stilbene and allyl chloride to temperature in n-heptane has been investigated and the activation energies (E) and preexponential factors (A) determined.
Abstract: Unlike the case of the well-studied relation of the rate of reaction of O/sub 3/ with olefins to temperature in the gas phase for solution where the reaction proceeds approx.10 times as fast as in the gas phase, there are only approximate data indicating the values of the activation energies in the range of 0-8 kJ/mole at 77-330/sup 0/K. The relation of the rate constant to temperature has been elucidated only for relatively slow reactions of O/sub 3/ with maleic anhydride, maleic and fumaric acids and trichloroethylene. In the present paper, the relation of the rate of reaction of O/sub 3/ with stilbene and allyl chloride to temperature in n-heptane has been investigated and the activation energies (E) and preexponential factors (A) determined. It has been found that the values of E for the solution are close to the upper limit of the published values for the gas phase, while A exceeds the corresponding values by 1-3 orders.
29 citations
11 citations
TL;DR: In this article, it was shown that the oxirane rings may react at high temperature with the cyanurate rings to form isocyanurate fragments, which, in turn, react with excess epoxide to form oxazolidone rings.
Abstract: In the case of the reaction of triphenylcyanurate and phenyl glycidyl ether, we showed that the oxirane rings may react at high temperature with the cyanurate rings to form isocyanurate fragments, which, in turn, react with excess epoxide to form oxazolidone rings.
10 citations
TL;DR: In this article, arylphosphonates were obtained in the presence of aromatic hydrocarbons at glass-carbon electrodes with the addition of Na3PO4, which gave high yields.
Abstract: Electrochemical oxidation of trialkyl phosphites in the presence of aromatic hydrocarbons at glass-carbon electrodes with the addition of Na3PO4, gives arylphosphonates in high yields.
9 citations
TL;DR: In this article, it was shown that 1,5-Diaza-3,7-diphosphacyclooctanes have crown conformation in solution and have groups which leave upon nucleophilic attack at two carbon atoms attached to the phosphorus atom and amines with two labile N-R bonds.
Abstract: 1.
1,5-Diaza-3, 7-diphosphacyclooctanes may be prepared from phosphines having groups which leave upon nucleophilic attack at the two carbon atoms attached to the phosphorus atom and amines with two labile N-R bonds.
2.
1,5-Diaza-3,7-diphosphacyclooctanes have crown conformation in solution
.
9 citations
TL;DR: The carboxylic acids undergo both monodentate and bidentate chemisorption on the rutile surface, mono-dentate bonding being established either through the surface hydroxyl groups, or through the acid oxygen atoms and the surface titanium atoms as discussed by the authors.
Abstract: 1.
Coordinationally unsaturated titanium ions and surface hydroxyl groups serve as centers for the chemisorption of carboxylic acids on rutile. Oxygen atoms and residual hydroxyl groups, both on the solid surface and in the surface bound acid molecules, serve as centers for physical adsorption on the acid modified rutile surface.
2.
The carboxylic acids undergo both monodentate and bidentate chemisorption on the rutile surface, mono-dentate bonding being established either through the surface hydroxyl groups, or through the acid oxygen atoms and the surface titanium atoms.
3.
Methanol and water molecules partially displace chemisorbed acetic acid from the surface, forming surface methoxyl and hydroxyl groups, the displacement being much more pronounced with methanol than with water. Neither methanol nor water are capable of displacing chemisorbed stearic acid from the rutile surface.
8 citations
TL;DR: In this paper, Triphenylphosphine complexes of cyanomethyl gold and dichlorocyanomethynomethodine gold have been synthesized and shown to have linear coordination, the bond lengths and angles were typical for organic complexes of univalent gold.
Abstract: 1.
Triphenylphosphine complexes of cyanomethylgold and dichlorocyanomethylgold have been synthesized.
2.
The chemical properties of aurated acetonitrile were typical for σ organogold compounds but aurated dichloroacetonitrile recalled the chemical behavior of complex gold halides
3.
The gold atom in the molecule of dichlorocyanomethyl (triphenylphosphine) gold has linear coordination, the bond lengths and angles were typical for organic complexes of univalent gold.
7 citations
6 citations
TL;DR: In this article, the authors show that methyl esters of fluorine-containing α-keto acids react with hydrazine hydrate and ethylenediamine to give addition products at the α -keto group and at the same time the aminolysis products of the carbomethoxyl group.
Abstract: 1.
Methyl esters of fluoroalkyl-ontainingα-keto acids form addition products with acetamide at theα-keto group of the ester.
2.
Methyl esters of fluorine-containingα-keto acids react with hydrazine hydrate and ethylenediamine to give addition products at theα-keto group, and at the same time the aminolysis products of the carbomethoxyl group. Products of this type, formed from esters with a perfluorobutyl group, undergo haloformic decomposition.
3.
Methyl esters of fluoroalkyl-containingα-keto acids react with o-phenylenediamine to form 2-hydroxy-3-fluoroalkylquinoxalines.
6 citations
TL;DR: This article carried out the first reaction between pyrocatechol trifluoroacyl phosphite and chloral, and isolated an adduct in which the phosphorus atom, in contrast to the widely known Perkov reaction, retains its valence.
Abstract: We were the first to carry out the reaction between pyrocatechol trifluoroacyl phosphite and chloral, and isolated an adduct in which the phosphorus atom, in contrast to the widely known Perkov reaction [I], retains its valence. When equimolar amounts of pyrocatechol trifluoroacyl phosphite (I) and chloral are heated at I00-120~ pyrocatechol-O-(~-trifluoroacyloxy-B,~,B-trichloro)ethyl phosphite (II) is formed in a yield of 40%.
6 citations
TL;DR: In this article, a method for the preparation of difficulty-accessible allyl sulfones has been developed by the reaction of allyl ethers and esters, allylamines, and allyl sulphides with alkyl-and arylsulfinic acids catalyzed by palladium complex catalysts.
Abstract: A versatile method for the preparation of difficulty-accessible allyl sulfones has been developed by the reaction of allyl ethers and esters, allylamines, and allyl sulfides with alkyl- and arylsulfinic acids catalyzed by palladium complex catalysts.
TL;DR: In this paper, a method has been proposed for the synthesis of cyclopropane hydrocarbons on the basis of the stereo and regiospecific addition of alkyl, aryl, and vinyl Grignard reagents to the double bond.
Abstract: A method has been proposed for the synthesis of cyclopropane hydrocarbons on the basis of the stereo- and regiospecific addition of alkyl, aryl, and vinyl Grignard reagents to the double bond of cyclopropene hydrocarbons.
TL;DR: In this article, the composition of the surface layers formed when chromate solutions are applied to a magnesium alloy has been studied and the interaction results in the strong adsorption of the chromate with the reduction of chromium to the +3 oxidation state.
Abstract: 1.
The composition of the surface layers formed when chromate solutions are applied to a magnesium alloy has been studied.
2.
The interaction results in the strong adsorption of the chromate with the reduction of chromium to the +3 oxidation state.
3.
Chromate is weakly adsorbed on the surface of a magnesium alloy preliminarily oxidized in water, its amount on the surface is small, and its oxidation state is equal to +6.
4.
It has been postulated that the protective layer consists of a mixed oxide of magnesium and chromium.
TL;DR: The cis-products of the addition to cyanoacetylene of aziridines, diaziridine, imidazole, di-tert-butylamine, phosphines, and arsine are highly resistant to cis-trans isomerization.
Abstract: 1.
High trans-stereospecificity has been shown in the addition to cyanoacetylene of: a) secondary aliphatic amines, with cooling, and b) under the usual conditions with sterically hindered amines, phosphines, mercaptan, and arsine, and also with amines with reduced positive mesomeric capacity of the nitrogen atom.
2.
The cis-products of the addition to cyanoacetylene of aziridines, diaziridine, imidazole, di-tert-butylamine, phosphines, and arsine are highly resistant to cis-trans isomerization. In cis-β-di-tert-butylaminoacrylonitrile, amide-type conjugation is sterically hindered.
TL;DR: In this article, a study was carried out on the oxidation of polyunsaturated ethers and esters by molecular oxygen catalyzed by the PdCl2-CuCl system.
Abstract: 1.
A study was carried out on the oxidation of polyunsaturated ethers and esters by molecular oxygen catalyzed by the PdCl2-CuCl system. A series of new mono-, di-, and triketoethers and triketoesters was obtained in high yield.
2.
A synergistic effect of quaternary ammonium salts was found in the oxidation by molecular O2 leading to an increase in the yield of carbonyl compounds.
TL;DR: By the reaction of 2,2′-dilithiumbiphenyl with lanthanide bromides, previously unknown organic derivatives of lanthanides which contain the metal in the ring have been prepared.
Abstract: By the reaction of 2,2′-dilithiumbiphenyl with lanthanide bromides, previously unknown organic derivatives of lanthanides which contain the metal in the ring have been prepared.
TL;DR: In this article, Diethylaminomagnesium hydride in the presence of Cp2TiCl2 regioselectively hydromagnesates 1-alkenes was given.
Abstract: Diethylaminomagnesium hydride in the presence of Cp2TiCl2 regioselectively hydromagnesates 1-alkenes to give diethylaminomagnesium alkyls.
TL;DR: Bis(1,2-dimethyl-o-carborane) is formed when 1,2 -dimethyl carborane is oxidized by thallium(III) trifluoroacetate in the presence of 10% of Pd(II) acetate in CF3COOH solution as discussed by the authors.
Abstract: Bis(1,2-dimethyl-o-carborane) is formed when 1,2-dimethyl-o-carborane is oxidized by thallium(III) trifluoroacetate in the presence of 10% of Pd(II) acetate in CF3COOH solution.
TL;DR: Diethylmagnesium adds regiospecifically to α-olefins in the presence of catalytic amounts of Cp2ZrCl2 to give difficultly available higher dialkyl organomagnesium compounds as mentioned in this paper.
Abstract: Diethylmagnesium adds regiospecifically to α-olefins in the presence of catalytic amounts of Cp2ZrCl2 to give difficultly available higher dialkyl organomagnesium compounds.
TL;DR: From the study of the chemical properties of B-stannylated carboranes and their Mossbauer spectra, it was shown that these compounds contain a stable boron-tin bond and manifest properties of organotin compounds as mentioned in this paper.
Abstract: 1.
Carboranyl derivatives with a boron-tin bond were obtained.
2.
From the study of the chemical properties of B-stannylated carboranes and their Mossbauer spectra, it was shown that these compounds contain a stable boron-tin bond and manifest properties of organotin compounds.
TL;DR: In this paper, the electron impact approach was used to investigate the processes of formation of positive and negative ions in the mass spectra of perchloryl fluoride and chlorosyl fluoride.
Abstract: The electron impact approach was used to investigate the processes of formation of positive and negative ions in the mass spectra of perchloryl fluoride and chlorosyl fluoride. The bond energies F-ClO, Cl-OF, O-ClF, O,O-Cl0F, O-Cl0[2F, and P-Cl03 have been calculated, as well as the heat of formation of Cl0F, the lower limits of electron affinity of the molecules OF, Cl02F, Cl02, and Cl03, and the ionization potential of the Cl03 molecules. The ionization potential of the Cl0F molecule was also measured.
TL;DR: The hydrogenation of fluoroolefins on palladium catalysts proceeds with rigorous steric specificity as discussed by the authors, and higher internal perfluoroole fins are readily reduced by catalytic hydrogenation and treatment with complex metal hydrides.
Abstract: 1.
Higher internal perfluoroolefins are readily reduced by catalytic hydrogenation and treatment with complex metal hydrides.
2.
The hydrogenation of fluoroolefins on palladium catalysts proceeds with rigorous steric specificity.
TL;DR: In this article, a method for oxidation by oxygen of carbanions obtained from di-and triarylmethanes in the system KOH-DME-18crown-6-ether was developed.
Abstract: 1.
We have developed a method for oxidation by oxygen of carbanions obtained from di-and triarylmethanes in the system KOH-DME-18-crown-6-ether. The reaction products are diarylketones and triarylcarbinols.
2.
Under the reaction conditions, diarylketones (XC6H4)2CO may be converted to triarylcarbinols (X=H, F, Br). Under the same conditions, (NO2C6H4)2 CO is cleaved with formation of p-nitrophenol and p-nitrobenzoic acid.
3.
In the case of tris(p-nitrophenyl)carbinolate we have shown the exceptionally strong dependence of the stability of the carbinolate on the counterion: potassium carbinolate is cleaved in the presence of O2 with formation of p-NO2C6H4OH and p-NO2C6H4COOH, lithium carbinolate is stable.
TL;DR: The radiolysis of perfluorinated compounds leads to the formation of radicals which are stable not only in the liquid phase in solutions but also in the gas phase as discussed by the authors.
Abstract: 1.
The radiolysis of a series of individual perfluorinated compounds leads to the formation of radicals which are stable not only in the liquid phase in solutions but also in the gas phase.
2.
The discovered stable radicals do not react with oxygen either during prolonged storage or during γ irradiation at 300°K.
3.
The radiolysis of the compounds in the liquid and solid phases leads to the formation of various unstable radicals.
TL;DR: Fluorenyl derivatives of lanthanides were synthesized for the first time in this paper, and their structure was confirmed by IR and PMR spectra, and their properties were shown to be stable.
Abstract: Fluorenyl derivatives of lanthanides were synthesized for the first time. Their structure was confirmed by IR and PMR spectra.
TL;DR: The 5-amino-4-acetylenylpyrazoles do not cyclize under analogous conditions as mentioned in this paper, unlike the o-acetelenyl derivatives of the pyrrolo-pyrazole system.
Abstract: 1.
4-Amino-5-acetylenylpyrazoles are capable of isomerizing in the presence of Cu(I) salts, with closure of the pyrrole ring and formation of the condensed pyrrolo[3,2-c]pyrazole system.
2.
The 5-amino-4-acetylenylpyrazoles, in contrast to the 4-amino-5-acetylenyl derivatives, and also the o-acetylenylanilines, do not cyclize under analogous conditions.
TL;DR: In this paper, it is suggested that the constants that characterize adsorption dynamics in the layer-by-layer adaption dynamics model be expressed in terms of length, where the output concentration is numerically equal to the concentration in equilibrium.
Abstract: 1.
It is suggested that the constants that characterize adsorption dynamics in the layer-by-layer adsorption dynamics model be expressed in terms of length. The kinetic constant is defined as the equilibrium adsorption layer Le where the output concentration is numerically equal to the concentration in equilibrium with the mean adsorption level of that layer.
2.
The initial equation combines the features of a material-balance equation and the adsorption kinetics and isotherm.
3.
The results of numerical calculations for a convex, a linear, and a concave adsorption isotherm agree closely with experimental data.
TL;DR: It has been shown that side reactions of 4-pentenal leading to cyclopentanone and 2-propenyl-6-heptene-1,3-diol are caused by cobalt hydride complexes formed as intermediates as discussed by the authors.
Abstract: 1.
By the example of cyclization of 4-pentenal into cyclopentanone it has been shown that the complexes Co(PPh3)4 and Co2(N2)(PPh3)6 catalyze the reaction of intramolecular hydroacylation.
2.
It has been established that side reactions of 4-pentenal leading to 4-pentene-1-diol, 2-propenyl-2,6-pentadienal, and mono(4-pentenoates) of 2-propenyl-6-heptene-1,3-diol are caused by cobalt hydride complexes formed as intermediates.
TL;DR: In this article, conditions for the liquid phase catalytic reduction of aromatic nitro compounds have been shown to have a different effect on the hydrogenation of the compounds to the corresponding arylhydroxylamine and on the disproportionation with the formation of amines.
Abstract: 1.
It has been shown that conditions for the liquid-phase catalytic reduction of aromatic nitro compounds have a different effect on the hydrogenation of the nitro compounds to the corresponding arylhydroxylamine and on the disproportionation of the latter with the formation of amines.
2.
Contrary to the hydrogenation of the nitro group, the disproportionation rate of the arylhydroxylamines depends to a large degree on the temperature and the pH of the medium. Electron-donor substituents increase the disproportionation rate, while electron-acceptor substituents reduce it.
3.
The conditions have been determined at which an increased yield of arylhydroxy1amines is obtained in the catalytic reduction of the nitro compounds.