Showing papers in "Russian Chemical Bulletin in 1986"
TL;DR: In this article, a system of parameters for the calculation of standard enthalpies of formation of organic compounds has been developed, which is based on group increments and it has been shown that in order to obtain accuracy close to the experimental value it is necessary to introduce corrections accounting for the interaction between the functional groups.
Abstract: A system of parameters for the calculation of standard enthalpies of formation of organic compounds has been developed. The system is based on group increments. It has been shown during the calculation of enthalpy of formation of polyfunctional compounds that in order to obtain accuracy close to the experimental value it is necessary to introduce corrections accounting for the interaction between the functional groups.
20 citations
TL;DR: In this article, two methods have been developed for the preparation of 1-ethynyl-o-, m-, and p-carboranes: reaction of 1 o-, m, and p carboranylcopper derivatives with 1-bromo-2-trimethylsilylacetylene and subsequent decomposition of the C-Si bond in the trimethyl silylethynyl carboranes with either ethanolic base or KF in a two-phase system.
Abstract: Two methods have been developed for the preparation of 1-ethynyl-o-, m-, and p-carboranes: reaction of 1-o-, m-, and p-carboranylcopper derivatives with 1-bromo-2-trimethylsilylacetylene and subsequent decomposition of the C-Si bond in the trimethylsilylethynyl-carboranes with either ethanolic base or KF in a two-phase system, and, secondly, reaction of 1-o-, m-, and p-carboranylcopper with trans-1-halo-2-iodoethylenes (halogen=Cl or I), followed by dehydrohalogenation of the resulting 1-(trans-β-halovinyl)carboranes with sodium amide in liquid ammonia.
17 citations
TL;DR: In this article, a new method for the measurement of adsorption on entirely microporous adsorbents permits the study of the absolute adorption of gases and vapors in a broad range of ad-sorption equilibrium parameters.
Abstract: 1.
The use of a new method for the measurement of adsorption on entirely microporous adsorbents permits the study of the absolute adsorption of gases and vapors in a broad range of adsorption equilibrium parameters.
2.
The methane adsorption isosteres on PAU-10 microporous activated charcoal are satisfactorily approximated by straight lines in the entire temperature range (120–600‡K) and pressure range (0.1 Pa – 20 MPa). The adsorption isosteres interrupted on the saturated vapor pressure line then extend linearly in the hypercritical region.
14 citations
12 citations
TL;DR: The enthalpies of formation of 13 ketene and ethynol analogs containing O, N, and S atoms were calculated in this paper, where they were obtained: ΔHf°(CH2=C=0) ≤ -8724 kJ/mole and ΔHmF°(HC2=COH) = +416 kJ /mole.
Abstract: 1
Enthalpies of formation were obtained: ΔHf°(CH2=C=0) ≤ -8724 kJ/mole and ΔHf° (HC=COH) = +416 kJ/mole
2
The enthalpies of formation of 13 ketene and ethynol analogs containing O, N, and S atoms were calculated
12 citations
TL;DR: In this paper, a reaction was carried out in a medium of the organic nitrile in a sealed glass ampul at 180~ for 12 h. The melting point of (I) was 40-41~ [i], while the boiling point was I00I02~ (2 mm) [2].
Abstract: This reaction was carried out in a medium of the organic nitrile in a sealed glass ampul at 180~ for 12 h. After removal of the excess nitrile, the product was extracted with hexane and purified by thin-layer chromatography on silica gel using 2:1 benzene-hexane as the eluent. The melting point of (I) was 40-41~ [i], while the boiling point of (II) was I00I02~ (2 mm) [2]. The structures of (I) and (II) were supported by their IR and PMR spectra.
10 citations
TL;DR: In this article, the rate constants for the reactions of OH, HSO4, NO3, and Cl2 radicals with neptunoyl ions were derived using the Pulse Radiolysis (PRS) algorithm.
Abstract: 1. Pulse radiolysis was used to find the rate constants for the reactions of OH, HSO4, NO3, and Cl2 radicals with neptunoyl ions.
9 citations
TL;DR: In this paper, the possibility of obtaining only one ion in the mass spectra was demonstrated in conditions of ionization with UV radiation at atmospheric pressure: the M + ion for n-alkanes and the MH+ ion for alcohols, ketones, esters, and amines.
Abstract: 1.
The possibility of obtaining only one ion in the mass spectra was demonstrated in conditions of ionization with UV radiation at atmospheric pressure: the M+ ion for n-alkanes and the MH+ ion for alcohols, ketones, esters, and amines.
2.
Ionization with UV radiation at atmospheric pressure permits broadening the linear range by 104–106 times and decreasing the limit of detection ∼102 times in comparison to the existing methods of mass spectral analysis with ionization at atmospheric pressure and by 102–104 and 102 times in comparison to chemical ionization in comparable conditions.
3.
The possibility of mass spectrometric analysis of submicrogram quantities of the components of mixtures without preliminary separation was demonstrated on the example of n-alkanes and aromatic hydrocarbons in conditions of ionization with UV radiation.
9 citations
TL;DR: The KOH-DMSO pair is an example of the superbasic medium which is simplest to prepare and use; its basicity is located between potassium tert-butylate and potassium dimsyl in DMSO.
Abstract: 1.
Saturated solutions of alkali metal hydroxides in dimethyl sulfoxide are highly basic. The values of the acidity function H varied from 20.5 to 30.5 in going from LiOH to KOH.
2.
The strong dependence of the basicity of the alkali-DMSO system on the nature of the cation is the result of an ion pair interaction in the solution which increases with a decrease in the radius of the cation and the varied drying capacity of the alkalis present in excess.
3.
The KOH-DMSO pair is an example of the superbasic medium which is simplest to prepare and use; its basicity is located between potassium tert-butylate and potassium dimsyl in DMSO.
9 citations
9 citations
TL;DR: In this article, metal exchange in DMSO (K+ cation) pK values have been measured for a series of acids which are Ni(II) complexes of Schiffs bases of the amino acids Gly, S-Ala, and S-Val.
Abstract: 1.
By metal exchange in DMSO (K+ cation) pK values have been measured for a series of acids which are Ni(II) complexes of Schiffs bases of the amino acids Gly, S-Ala, and S-Val, with S-2-N-(N′-benzylprolyl)arainobenzaldehyde and S-2-N-(N′-benzylprolyl)aminobenzo-phenone.
2.
The amino acid fragment in the studied Ni(II) complexes possesses high acidity close to fluorene but five orders of magnitude greater than for acetophenone and approaching nitroalkanes in acidity.
TL;DR: In this article, the reaction of carboranyl boron-centered radicals with phosphites occurs through the formation of a phosphoranyl radical, and the addition of the radicals derived from 2,6,7-tris(trichloromethyl)-3,5,8-trioxo-1,4-diphosphabicyclo[2.2] octane to 3,6-di-tert-butyl-ortho-benzoquinone was detected.
Abstract: 1.
The preparative photolysis of bis(m-carboran-9-yl)mercury and bis(p-carboran-2-yl)-mercury with trimethyl phosphite leads to the dimethyl esters of m- and p-B-carboranylphosphonic acids.
2.
The reaction of carboranyl boron-centered radicals with phosphites occurs through the formation of a phosphoranyl radical.
3.
The addition of the phosphoranyl radicals derived from 2,6,7-tris(trichloromethyl)-3,5,8-trioxo-1,4-diphosphabicyclo[2.2.2]octane to 3,6-di-tert-butyl-ortho-benzoquinone was detected. ESR spectroscopy was used to observe the tautomeric transfers of the phosphoranyl group between the ortho-benzoquinone oxygen atoms.
TL;DR: In this paper, N-Chloro-N-alkoxyureas were synthesized for the first time, and from them previously unknown N,N-dialkoxyurea were obtained by nucleophilic substitution reactions.
Abstract: 1.
N-Chloro-N-alkoxysulfonamides and N-chloro-N-alkoxyphosphoamides have chlorinating properties in the reaction with triethylamine in methanol.
2.
N-Chloro-N-alkoxyureas were synthesized for the first time, and from them previously unknown N,N-dialkoxyureas were obtained by nucleophilic substitution reactions.
TL;DR: The reaction of vicinal dihalopolyfluoroalkanes and related compounds with sodium azide causes replacement of halogen by an azide group, probably by an ionic cleavage-addition chain mechanism as discussed by the authors.
Abstract: 1.
The reaction of vicinal dihalopolyfluoroalkanes and related compounds with sodium azide causes replacement of halogen by an azide group, probably by an ionic cleavageaddition chain mechanism.
2.
Nucleophilic azidobromination of fluoroolefins has been carried out by the action of sodium azide and bromine.
3.
These reactions were used to synthesize new β-halopolyfluoroalkyl azides.
TL;DR: In this article, the effective rate constants of the formation and hydrolysis of acid methyl sulfate and the ratio of the equilibrium concentrations of the alcohol and the acid sulfate in solutions of D2SO4 in D2O were measured at 25°C by the PMR method.
Abstract: 1.
The effective rate constants of the formation and hydrolysis of acid methyl sulfate and the ratio of the equilibrium concentrations of the alcohol and the acid methyl sulfate in solutions of D2SO4 in D2O with D2SO4 concentrations from 9.24 to 13.28 mole/liter were measured at 25°C by the PMR method. The limiting stage of the hydrolysis is dissociation of a complex consisting of acid methyl sulfate and the D5O2+ ion.
2.
The available data on the formation and hydrolysis of the acid ethyl sulfate and acid 2,4-dinitrobenzyl sulfate in aqueous H2SO4 solutions at 25°C and 0°C were analyzed.
TL;DR: A new source of unhydrated fluoride Ion, hexamethylguanidinium fluoride, has been synthesized as discussed by the authors, which adds practically irreversibly to perfluoroisobutylene to form the perfluoro-tert-butyl anion that is stabilized by the hexamethylamylguanidine cation.
Abstract: 1.
A new source of unhydrated fluoride Ion, hexamethylguanidinium fluoride, has been synthesized.
2.
Hexamethylguanidinium fluoride adds practically irreversibly to perfluoroisobutylene to form the perfluoro-tert-butyl anion that is stabilized by the hexamethylguanidinium cation.
3.
Direct acylation of perfluoro-tert-butyl anion, to give phenyl perfluoro-tert-butyl ketone has been carried out for the first time.
TL;DR: In this article, a solution of PtCl62− ions and toluene in CF3CO2H-H2O leads to the formation of a platinum(IV) σ-tolyl complex which decomposes in the presence of free toluenes.
Abstract: Heating a solution of PtCl62− ions and toluene in CF3CO2H-H2O leads to the formation of a platinum(IV) σ-tolyl complex which decomposes in the presence of free toluene to give 3,3′-, 4,4′-, 3,4′-, 2,3′- and 2,4′-ditolyls.
TL;DR: In this paper, a method for determining the specific volume of microporous adsorbents with micropores based on high-temperature helium pycnometry of the adsorbent and measurement of the excess adsorption of vapor and liquid was proposed.
Abstract: 1.
A method for determining the specific volume of microporous adsorbents with micropores based on high-temperature helium pycnometry of the adsorbent and measurement of the excess adsorption of vapor and liquid was proposed.
2.
High-temperature helium pycnometry makes it possible to experimentally establish the dividing surface and to specify the measured excess adsorption values.
3.
The proposed method permits making the measurement of the absolute adsorption in microporous adsorbents more precise.
TL;DR: In this article, a nucleophilic substitution of the chlorine atom at the N atom takes place to form N-alkoxyhydrazines, which are stable in the reaction with Me3N, pyridine, toluenesulfonamides, and give products of further transformations with Me2NH and MeONHMe.
Abstract: In the reaction of N-chloro-N-methoxy-N′,N′-dimethylurea with amines, a nucleophilic substitution of the chlorine atom at the N atom takes place to form N-alkoxyhydrazines, which are stable in the reaction with Me3N, pyridine, toluenesulfonamides, and give products of further transformations with Me2NH and MeONHMe.
TL;DR: In the preparation of zinc alumocalcium chemisorbents, reactions take place during mixing of the zinc component with the carrier in the aqueous ammonium medium, which lead to the formation of phases of zinc hydroxoaluminate, gibbsite, zinc hydoxide, calcite, an ammonia-carbonate zinc complex, and tricalcium aluminate hexahydrate as mentioned in this paper.
Abstract: 1.
In the preparation of zinc alumocalcium chemisorbents, reactions take place during mixing of the zinc component with the carrier in the aqueous ammonium medium, which lead to the formation of phases of zinc hydroxoaluminate, gibbsite, zinc hydroxide, calcite, an ammonia-carbonate zinc complex, and tricalcium aluminate hexahydrate.
2.
The degree of combination of the zinc component into the zinc hydroxoaluminate depends on the degree of hydration of the carrier and decreases in the order: calcium mono-aluminate > calcium dialuminate > aluminum oxide > Galumin.
3.
In the thermolysis the zinc hydroxoaluminate is converted to dispersed zinc oxide and disordered zinc-aluminum spinel, the amount of which depends on the nature of the carrier.
4.
The sulfur capacity of the zinc chemisorbents depends on the zinc oxide content and on the amount of the free zinc oxide phase; it changes antibatically to the ability of the carrier to bind the zinc component into zinc hydroxoaluminate and zinc-aluminum spinel.
TL;DR: The thermolysis of 1-vinylcyclobutene at 335°C under flash conditions gave a quantitative yield of 3-methylene-l,4-pentadiene.
Abstract: 1.
The thermolysis of 1-vinylcyclobutene at 335°C under flash conditions gave a quantitative yield of 3-methylene-l,4-pentadiene.
2.
The anionic polymerization of 1-vinylcyclobutene proceeds with retention of the fourmembered ring.
TL;DR: In this article, a new method was developed for the synthesis of 3-amino-5-benzylamino4-nitropyrazole, which is the first step of this procedure is the preparation of l,l-di(alkylamino)-2nitro-2-cyanoethylenes by the condensation of nitroacetonitrile with isothiourea derivatives.
Abstract: A new efficient method has been developed for the synthesis of 3-amino-5-benzylamino4-nitropyrazole. The key step of this procedure is the preparation of l,l-di(alkylamino)-2nitro-2-cyanoethylenes by the condensation of nitroacetonitrile with isothiourea derivatives.
TL;DR: The Arbuzov reaction and alkylation by ω-haloalkylphosphonic esters gave diesters of aminooxymethane, β-aminooxyethane-, and β-amide-butanephosphonic acids as discussed by the authors.
Abstract: The Arbuzov reaction and alkylation by ω-haloalkylphosphonic esters gave diesters of aminooxymethane-, β-aminooxyethane-, and β-aminooxybutanephosphonic acids; aminooxymethane- and β-aminooxyethanephosphonic acids; and monoesters of β-aminooxyethanephosphonic acid.
TL;DR: The adsorption of ozone on silica gel gives singlet oxygen (1Δg) identified by its IR luminescence at 1720 nm and reaction with biadamantylidene to give 1,2-dioxetane.
Abstract: The adsorption of ozone on silica gel gives singlet oxygen (1Δg) identified by its IR luminescence at 1720 nm and reaction with biadamantylidene to give 1,2-dioxetane.
TL;DR: The configurational stability of the N atom in NH-dialkoxyamines and their derivatives has been determined by NMR as discussed by the authors, and their reactions with nucleophiles and electrophiles have been studied.
Abstract: 1.
Alkaline hydrolysis of N,N-dialkoxy-N′,N′-dimethylureas gives NH-dialkoxyamines.
2.
N-Hydroxymethyl- and N-aminomethyl-N,N,-dialkoxyamines have been synthesized and their reactions with nucleophiles and electrophiles have been studied.
3.
The configurational stability of the N atom in NH-dialkoxyamines and their derivatives has been determined by NMR.
TL;DR: In this paper, the average densities of adsorbates at p =ps in the pores of zeolites and the temperature dependences of the adsorption values were determined for the previously studied argon, krypton, xenon-NaX zeolite, CO2-NX, and trifluor-ochloromethane-naX systems and for the newly studied H2O-NaA zeolitic and ethanol-naphase-enhanced Zeolite systems.
Abstract: 1.
The average densities of adsorbates at p=ps in the pores of zeolites and the temperature dependences of the adsorption values were determined for the previously studied argon, krypton, xenon-NaX zeolite, CO2-NaX, and trifluorochloromethane-NaX systems and for the newly studied H2O-NaA zeolite and ethanol-NaX zeolite systems.
2.
The values of the average densities and their temperature coefficients were compared with the values calculated with the Dubinin-Nikolaev and Basmadjian-Cook methods. It was shown that there are significant differences between the measured and calculated values.
3.
It was shown that the value of the average densities of the adsorbates and their thermal expansion coefficients differ significantly from the corresponding values for normal bulk liquid phases.
4.
It was found that for all nonpolar adsorbates, there is a temperature at which the densities of the ads.orbate and the corresponding liquid are equal. This point, expressed in a reduced temperature scale (τ=T/Tcr), is equal to 0.88 ± 0.04.
5.
The average density of water adsorbed by zeolite at all temperatures is greater than the density of liquid water.
TL;DR: A ternary complex of cobalt phthalocyanine with thiolate and oxygen is formed during contact with oxygen in the presence of excess thiolates ions as mentioned in this paper.
Abstract: 1.
Cobalt(II) phthalocyanine undergoes a one-electron reduction by sodium mereaptide in a N,N-dimethylformamide medium under anaerobic conditions.
2.
A ternary complex of cobalt phthalocyanine with thiolate and oxygen is formed during contact with oxygen in the presence of excess thiolate ions. The complex has sensitivity to light and decomposes in the presence of aqueous alkali. The alternative possibility of a formation of a dithiolate derivative of cobalt(III) is less probable.
TL;DR: The geometric structure and thermochemistry of linear and branched saturated acyclic hydrocarbons are accurately described with the aid of molecular mechanics in the MM/2 parametrization, while the semi-empirical quantum-chemical methods are less effective as mentioned in this paper.
Abstract: 1.
The geometric structure and thermochemistry of linear and branched saturated acyclic hydrocarbons are accurately described with the aid of molecular mechanics in the MM/2 parametrization, while the semiempirical quantum-chemical methods are less effective.
2.
For the calculation of the electronic structure of saturated acyclic hydrocarbons it is most expedient to use semiempirical quantum-chemical methods with the values of the geometric parameters optimized in the framework of the MM/2 method.