Showing papers in "Russian Chemical Bulletin in 1973"
TL;DR: In this paper, the x-ray electron spectroscopy method was used to study the rhenium sulfides, which function as liquid-phase hydrogenation catalysts, before and after the catalysis of cyclohexene and a number of pyridine bases under the conditions of high temperatures and high hydrogen pressure.
Abstract: 1.
Employing the x-ray electron spectroscopy method, we made a study of the rhenium sulfides, which function as liquid-phase hydrogenation catalysts, before and after the catalysis of cyclohexene and a number of pyridine bases under the conditions of high temperatures and high hydrogen pressure.
2.
A change in the energy value of the Re4f7/2 bond in rhenium sulfides was detected before and after catalysis, and during reaction with hydrogen.
3.
Sulfate ions were detected in comparable amounts in the surface layer of rhenium sulfides, the amount of which decreases as the result of the action of hydrogen.
32 citations
11 citations
TL;DR: In this article, the influence of azasubstitution on the electronic absorption spectra of phthalocyanin molecules was investigated, and it was shown that the long-wave absorption bands undergo a substantial hypsochromic shift, the value of which depends on the number of supplementary nitrogen atoms and on their position.
Abstract: 1.
Some new tert-butyl-substituted azaanalogs, possessing increased solubility in organic solvents, were synthesized for a study of the influence of azasubstitution on the electronic absorption spectra of phthalocyanin.
2.
Azasubstitution in the phthalocyanin molecules does not change the position of the absorption bands in the near UV region, while the long-wave absorption bands undergo a substantial hypsochromic shift, the value of which depends on the number of supplementary nitrogen atoms and on their position.
3.
These peculiarities of the spectra of phthalocyanins are explained by the nature of the molecular orbitals, between which the correspondingπ-electronic transitions occur.
9 citations
9 citations
8 citations
TL;DR: In this article, the positions of the maxima of the effective yield of the (M-H)− ions on the energy scale of the electrons for condensed hydrocarbons and biphenyl coincide with the maximum yield of (M −H− ions for benzene.
Abstract: The positions of the maxima of the effective yield of the (M-H)− ions on the energy scale of the electrons for condensed hydrocarbons and biphenyl coincide with the maximum yield of the (M-H)− ions for benzene. The existence of a molecular ion M−, with a life span with respect to autoionization of 21Μsec, was observed for anthracene.
7 citations
TL;DR: In this paper, the pyrolysis of mercury trifluoroacetate and phenylmercury trifluroacetate in the presence of K2CO3 was shown to yield high yields.
Abstract: 1.
The pyrolysis of mercury trifluoroacetate and phenylmercury trifluoroacetate in the presence of K2CO3 respectively gave bis(trifluoromethyl)mercury and phenyltrifluoromethylmercury in high yields.
2.
Bis(trifluoromethyl)mercury can serve as a source of difluorocarbene.
7 citations
TL;DR: The perfluoroisobutylene-triethylamine mixture is a mild dehydrofluorinating agent as discussed by the authors, which is used in the synthesis of bis(trifluoromethyl)ketenimines.
Abstract: 1.
Methods were developed for the synthesis of bis(trifluoromethyl)ketenimines by the reaction of perfluoroisobutylene with primary amines, or by the dehydrofluorination of the imidoyl fluorides ofα-hydroperfluoroisobutyric acid.
2.
The perfluoroisobutylene-triethylamine mixture is a mild dehydrofluorinating agent.
6 citations
TL;DR: In this paper, a comparative evaluation of the effectiveness of various catalytic systems in the polycyclotrimerization reaction is cited, and the processes of their decarboxylation are studied.
Abstract: 1.
The oxidation of oligophenylenes, produced by the reaction of polycyclotrimerization, was studied.
2.
Oligophenylenecarboxylic acids were produced, and the processes of their decarboxylation were studied.
3.
A comparative evaluation of the effectiveness of various catalytic systems in the polycyclotrimerization reaction is cited.
5 citations
TL;DR: In the case of pulsed illumination of symmetrical cyanine dyes, there are transitory reversible changes in the absorption spectrum due to the formation of photoisomers as discussed by the authors.
Abstract: 1.
In the case of pulsed illumination of symmetrical cyanine dyes, there are transitory reversible changes in the absorption spectrum, due to the formation of photoisomers. For carbocyanine molecules with a substituent in the meso-position, as well as for thiamonomethinecyanine, an extremely low value of the quantum yield of photoisomerization was detected.
2.
Cis-trans-photoisomerization occurs at the singlet excited level.
3.
Measurements of the kinetics of relaxation revealed a first order of the reaction, in accord with the monomolecular process: trans(cis) ⇝ cis(trans).
5 citations
TL;DR: In this article, the ionization potential of some phenothiazine derivatives (PTD) were calculated from the optical spectra of the charge transfer complexes, and the obtained values were compared with the indices that characterize the cholinolytic and antiarrhythmic properties of PTD, and it was concluded that a relation exists between them.
Abstract: 1.
The ionization potentials (I) of some phenothiazine derivatives (PTD) were calculated from the optical spectra of the charge-transfer complexes.
2.
The obtained values were compared with the indices that characterize the cholinolytic and antiarrhythmic properties of the PTD, and it was concluded that a relation exists between them.
TL;DR: The temperature limit for the heat stability of molecular water in a mordenite decreases in measure with the decationization and dealuminization as mentioned in this paper, which can be played by hydroxyl groups, sodium ions, or dehydroxylated centers that contain the aluminum ion.
Abstract: 1
The temperature limit for the heat stability of molecular water in a mordenite decreases in measure with the decationization and dealuminization
2
The dealuminization process is accompanied by a decrease in the number of hydrophilic centers, which role can be played by hydroxyl groups, sodium ions, or dehydroxylated centers that contain the aluminum ion
TL;DR: A study of the structure of 2,2′-dihydroxyazobenzene employing the methods of IR spectroscopy and LCAO MO as the Pariser-Parr approximation disclosed that this compound exists as a mixture of two tautomeric forms, the stability of which is approximately the same.
Abstract: A study of the structure of 2,2′-dihydroxyazobenzene employing the methods of IR spectroscopy and LCAO MO as the Pariser-Parr approximation disclosed that this compound exists as a mixture of two tautomeric forms, the stability of which is approximately the same.
TL;DR: In this paper, a study was made of the 1H, 13C, 14N and 29Si NMR spectra of some trimethylsilyl esters of nitronic acids.
Abstract: 1.
A study was made of the1H,13C,14N, and29Si NMR spectra of some trimethylsilyl esters of nitronic acids.
2.
A rapid intramolecular exchange of the trimethylsilyl group between the oxygen atoms of the O −N(O) fragment was observed.
TL;DR: The adsorbability of diethyl ether vapors on samples of H-mordenite with a high degree of dealumination is 30-40% higher than that of n-pentane vapors as mentioned in this paper.
Abstract: 1.
The adsorption of vapors of n-pentane and diethyl ether by sodium and modified hydrogen forms of mordenite experiences a strong kinetic inhibition, which makes it difficult to obtain reversible isotherms of equilibrium adsorption.
2.
Despite the low rate of adsorption and difficulty of achieving adsorption equilibrium, the bulk of the adsorbed substance is adsorbed at very low relative pressures.
3.
An increase in the degree of dealumination, leading to an enlargement of the micropores, promotes an increase in the magnitude and rate of adsorption of n-pentane and diethyl ether vapors.
4.
The adsorbability of diethyl ether vapors on samples of H-mordenite with a high degree of dealumination is 30–40% higher than that of n-pentane vapors.
TL;DR: In this article, the decomposition of NH4M is accompanied by the formation of several types of hydroxyl groups, which differ both in thermal stability and in rate of exchange with D2.
Abstract: 1.
It was shown on the basis of a study of the decomposition of the ammonium form of mordenite in various atmospheres by the methods of differential thermal analysis (DTA) and IR spectroscopy that when NH4M is heated to 400° there is a dehydration (stage I) of mordenite; in the interval 400–600° (in air) there is a deamination (stage II), and above 600° there is a dehydroxylation (stage III). In an atmosphere of nitrogen, deamination (stage II) occurs in a higher temperature (500–800°) than in air; the exothermic effect on the DTA curve at 500° is due to a process of oxidation.
2.
The decomposition of NH4M is accompanied chiefly by the formation of several types of hydroxyl groups, which differ both in thermal stability and in rate of exchange with D2.
3.
A comparison with the literature data indicates an increase in the strength of the NH4+ bond with the zeolite with increasing ratio SiO2/Al2O3 as a result of an increase in the acidity.
TL;DR: In this paper, the average life span of negative ions relative to autoionization on mass spectrometers equipped with a sector magnetic field was determined for azodiisobutyronitrile and the stable radicals of di-tert-butyliminoxyl and 2,2,6,6-tetramethylpiperidineiminoxideyl.
Abstract: 1.
A method was developed for determining the average life span of negative ions relative to autoionization on mass spectrometers equipped with a sector magnetic field.
2.
We measured the average life span of the molecular negative ions of azodiisobutyronitrile and the stable radicals of di-tert-butyliminoxyl and 2,2,6,6-tetramethylpiperidineiminoxyl.
TL;DR: The reduction rate of cyclohexanone with alcohols in the presence of RuCl2(PPh3)3 is independent of the length of the alkyl of the 2-n-alkanol (C4-C11), or of either the sec-butyl or cycloxide radical, but decreases sharply when going to the 3-, 4-, and 5-alkanols and 3, 3-dimethyl-2-butanol.
Abstract: 1.
The reduction rate of cyclohexanone with alcohols in the presence of RuCl2(PPh3)3 is independent of the length of the alkyl of the 2-n-alkanol (C4-C11), or of the presence of either the sec-butyl or cyclohexyl radical, but decreases sharply when going to the 3-,4-,and 5-alkanols and 3,3-dimethyl-2-butanol. The alkylphenylcartainols reduce ketones at a much faster rate than do the 2-alkanols, and they also promote the transformation of the latter.
2.
The reduction rate of ketones by alcohols, catalyzed by RuCl2(PPh3)3, decreases in the order; cyclohexanone > acetophenone > cyclopentanone > 2-hexanone ≥ cycloheptanone > cyclooctanone.
3.
The catalytic activity of RhCl(PPh3)3 in the hydrogen transfer reaction is higher than that of RuCl2(PPh3)3, and the reaction rate is but slightly dependent on the structures of the alcohol and the ketone.
TL;DR: In this paper, the effect of the N-oxide group on the orientation of electrophilic reactions that proceed both in the β-pyridinol ring and in the phenyl ring of the molecule was studied.
Abstract: 1
Some 2-aryl-3-hydroxypyridine N-oxides were synthesized
2
A study was made of the effect of the N-oxide group on the orientation in electrophilic reactions that proceed both in theβ-pyridinol ring and in the phenyl ring of the molecule The N-oxide group affects the reactivity of theβ-pyridinol ring and the orientation of the substitution only in the iodination reaction
TL;DR: In this paper, the bipolar ion with a P-C bond was used to form the enolic form of the dimethyl ester of 1, 2-diphenyl-3,5-pyrazolidinedione-4-benzylphosphonic acid.
Abstract: 1.
Trimethyl phosphite reacts with 1,2-diphenyl-4-benzal-3,5-pyrazolidinedione via the step of the bipolar ion with the formation of the methyl ether of the enolic form of the dimethyl ester of 1, 2-diphenyl-3,5-pyrazolidinedione-4-benzylphosphonic acid.
2.
The reaction of tri(dimethylamino)phosphine with 1,2-diphenyl-4-benzal-3,5-pyrazolidinedione gave a stable adduct (1:1), which has the structure of the bipolar ion with a P-C bond.
TL;DR: In this paper, four mechanisms for the adsorption of H2O molecules on various energetically homogeneous sections of the large cavities in zeolite NaX were examined.
Abstract: 1.
Employing a Tyan-Calvet calorimeter, a four-step curve was obtained for the differential adsorption heat of water on zeolite NaX.
2.
Four mechanisms for the adsorption of H2O molecules on various energetically homogeneous sections of the large cavities in zeolite NaX were examined.
TL;DR: The addition of small amounts of sodium metal changed the direction of the reaction and made it possible to obtain secondary alcohols as discussed by the authors, while tertiary alcohols were obtained by their oxidation.
Abstract: 1
Cyclic glycol esters of trialkylcarbinylboric acids were synthesized from trialkylboranes and carbon monoxide in 60–70% yield, while tertiary alcohols were obtained by their oxidation
2
The addition of small amounts of sodium metal changed the direction of the reaction, which made it possible to obtain secondary alcohols
TL;DR: In this article, the electric conductivity of molybdenum pentafluoride was measured in the temperature interval 70-150° and the complex formation of MoF5 with alkali metal fluorides was studied, and complex compounds with the composition MIMoF6 were isolated.
Abstract: 1.
The electric conductivity of molybdenum pentafluoride was measured in the temperature interval 70–150°.
2.
The complex formation of MoF5 with alkali metal fluorides was studied, and complex compounds with the composition MIMoF6 were isolated, where M=K, Rb, and Cs.
3.
The electric conductivity of liquid MoF5, as well as its tendency to undergo reactions of complex formation, are evidence of a tendency for coordination of the fluoride ion by molybdenum (V).
TL;DR: The extent of a new type of reaction between olefinα-oxides and β-hydroxyalkyl sulfides was shown in this article, where the structure of the formed olein oxide was determined by the β-hyl radical of the starting sulfide.
Abstract: 1.
The extent of a new type of reaction between olefinα-oxides andβ-hydroxyalkyl sulfides was shown.
2.
When olefinα-oxides are reacted withβ-hydroxyalkyl sulfides the structure of the formed olefin oxide is determined by the structure of theβ-hydroxyalkyl radical of the starting sulfide.
TL;DR: The lignin of the lignocarbohydrate complex, obtained by mechanical grinding from spruce wood, and of its low-molecular fraction, in its qualitative composition resembles spruce protolignin this paper.
Abstract: 1.
The lignin of the lignocarbohydrate complex, obtained by mechanical grinding from spruce wood, and of its low-molecular fraction, in its qualitative composition resembles spruce protolignin.
2.
The observed complete decomposition of the lignocarbohydrate linkages of the low-molecular fraction of the lignocarbohydrate complex under the influence of the e−+Na+ system makes it possible to assume that these linkages can be: aryl-O-aryl and aryl-O-alkyl, including aryl-O-benzyl, benzyl-O-alkyl, aryl-glycoside and benzyl-glycoside linkages.
3.
A dimer, representing a diphenylmethane derivative, was detected for the first time in the products obtained by the decomposition of the lignin of the lignocarbohydrate complex with sodium in liquid ammonia.
4.
On the basis of the molecular-weight distribution curves of the carbohydrate products of the decomposition it may be assumed that the lignin in the investigated lignocarbohydrate complex serves as a crosslink between two and more polysaccharide chains.