Acylation of amides substituted with pyridine-3-
sulfonic acids oxalil-chlorides and phosgene was
studied. New pyridil-3-sulfonil isocyanates were
synthesized. The conditions for this synthesis were
optimized by taking into account the detailed
understanding of this acylation. The synthesized
pyridine-3-sulfonyl isozyanates were converted to
pyridine-3-sulfonyl ureas. Biological activity of the
new compounds was studied and the substances with
high herbicidal effect were found
The current-voltage characteristics and the number of
effective ion transfer, as well as the frequency
spectrum of the electrochemical impedance of
multilayer ion-exchange membranes in a stable and
controllable thickness of the diffusion layer were
measured, using the of rotating membrane disk
complex. The article presents a comparative analysis
of the frequency spectra of the electrochemical
impedance of the source and a surface-modified
monopolar anion exchange membranes in 0.01 M
sodium chloride was made. The process of water
molecules dissociation at current densities above the
limiting one in 0.01 M sodium chloride solution was
studied in detail
This publication examines the relationship between the structure of molecules of complexing (descriptors of electronic structure), which are used as inhibitors of hydrogen embrittlement of the steel grade St3, and the content of absorbed hydrogen in model samples-plates made of the above steel. The form of expression of this relationship is the correlation coefficient (CC) by Pearson
The present article belongs to the area of organic chemistry, namely, to chemistry of heterocyclic compounds. For the purpose of optimization of a method of synthesis the threecyclic heteroaromatic systems containing a pyridi-ne, thiophen and pyrimidine ring in one molecule, - tetrahydropyridothienopyrimidinon and dihydropyri-dothienopyrimidinon – reaction 3-aminothieno[2,3-b]-pyridine-2-carbokxamides with aromatic aldehydes is studied, some of which contain pharmacolodical groups. Reaction was carried out in the conditions of an acid catalysis – is used p-TsOH. Influence of the nature of solvent (toluene, ethanol, mix ethanol-dimethilform-amide (1:1)) on the course and the direction of reaction are studied. It is established that carrying out reaction in toluene leads to the dihydropyrimidine containing in situation 2 phenyl, 4-bromphenyl deputies. In the presence in a molecule of initial aldehyde of the deputy in orto-situation tetrahydropyrimidine are formed. Use of ethanol mainly leads to formation of a tetrahydro-pyrimidine ring. Boiling of initial substances in mix ethanol-DMF yields the results similar to use of toluene, but time of reaction is reduced twice. The way of receiving the dihydroderivatives short-term boiling of tetrahydropyrimidine is found in mix isopropanol-DMF (a volume ratio of solvents 1:3). Identity of the received substances is proved by method of a thin layer chroma-tography. The structure of the synthesized connections is confirmed with the element analysis. The structure of tertagidropirimidinon and digidropirimidinon is proved with use of data of IK and NMR 1H of the spectral analysis
The new benzimidazole-functionalized graphene
material based on graphene oxide (GO) and 3,3',4,4'-
tetraaminodiphenyl oxide (TADPO) was obtained
under one-step hydrothermal synthesis conditions.
According to IR spectroscopy and elemental analysis,
as a result of the reaction, benzimidazole (BI) rings are
formed, and the mass content of nitrogen is 12.3%.
The new graphene material is characterized by
excellent electrochemical efficiency in a threeelectrode
supercapacitor. As a result of the redox
activity of BI cycles the specific capacitance reaches
286 F/g at the scan rate of 2 mV/s, which is
substantially higher than the reduced graphene oxide
(RGO) sample obtained under similar conditions
without using TADPO (159 F/g at 2 mV/s)
A number of thermoreactive oligomers was obtained
via the Michael interaction of molar excesses of
hexamethylene-bis-maleimide with 5,5’-bisbenzotriazoles
in melt. The structure of them was
proved by the 13C spectroscopy method. The one-step
synthesis in melt, without by-products evolution, in
absence of organic solvents, additional reagents, and
catalysts is the more acceptable in point of view of
technology (a finished reaction product does not
require any purification). The process itself is the
nucleophile addition across double bond, and so it can
be attributed to the atom-saving technologies.
According to data of the dynamic scanning calorimetry
(DSC) and the thermogravimetry (TG), oligomers fuse
at 130.8–135.6 °С, cross-link at 185–250 °С, and begin
their thermal destruction in air at temperatures of 400–
420 °С. The tensile strength at shear of the glued joints
on base of oligomers (steel plates overlapped) is 14.2–
23.7 MPa (142–237 kgf/cm2
). The positive effect from
the introduce of 5,5’-bis-benzotriazolyl fragments into
structure of bismaleimide thermoreactive oligomers on
strength of the glued joints between metal plates was
revealed
Surface energy of polymers determines such
important properties of polymers like wetability,
adhesion, ability adsorption of low molecular weight
substances. Inner organization, the structure of the
polymer and the dynamics of interaction between
macromolecular chains are shown at last. At the same
time, the micro-defects (inhomogeneity) of polymers,
which is an integral part of the structure are changed
during deformation and must contribute to changing
of the surface energy and its components.
This article solves the task of detecting changes in the
parameters of surface energy of polymers under
uniaxial deformation. Data for the quantitative
indicators of the surface properties total surface
energy and its dispersive and polar components are
presented. The calculations showed that the disperse
and polar components of all the samples of polymer
materials are about 98% of the total and, therefore, is
crucial. For the first time experimental data,
illustrating the change of surface energy of polymeric
materials had been obtained, including elastomeric
compositions, when uniaxial deformation. The
relative changes of the surface energy vary from 54.5
per cent to 125 %. A decrease of total surface energy
and its dispersion component is observed during
deformation of polymer samples of different structure
and chemical nature
In the article the mathematical model of the space charge region in the bipolar membrane is considered. The structure of the space charge region under passing of electric current, and without electric current is discussed. The results of experimental studies of water dissociation in the bipolar membrane in the presence of chromium(III) are discussed
The results of study of bipolar membrane – analogue
of MB-2, modified with chemically introduced chromium
(III), iron (III) and nickel (II) hydroxides by the
method of frequency spectrum of electrochemical impedance,
by infrared spectroscopy and scanning electron
microscopy in combination with X-ray spectrum
analysis are presented. It is shown, that sequential
treatment of cation-exchanger, contained in cationexchange
membrane, with metal salt solution and alkali
solution does not result in formation of complex
compounds of these metals with ionic groups of ion
exchanger. It was found that in these conditions the
presence of heavy metals in the phase of cationexchanger
confirmed by X-ray analysis, however,
crystals of hydroxides of heavy metals are not detected
in the size range of 1000 nm to 20 nm. These heavy
metal compounds are thermally unstable and their
catalytic activity in the reaction of dissociation of water
molecules decreases with increasing temperature
during heat treatment. The introduction of low-soluble
hydroxides of d-metals (chromium (III), iron (III),
nickel(II)) by chemical method can significantly improve
the electrochemical characteristics of a bipolar
membrane. The most effective catalysts in water dissociation
reaction are the hydroxides of chromium (III)
and iron (III) and, as a consequence, membranes with
these hydroxides have a lower value of overpotential
compared with original membrane at the same current
density
By the method of dipole moments, there has been determined that the tri-coordinated arsenic derivatives (p-XC6H4AsN-R)2 with R= Bu-t in the liquor exist in a cis-form, as for R=С6Н4Х-p the trans-structure is being realized. As for tetra-coordinated derivatives [XC6H4As(S)NBu-t]2 the trans-form is also beeing observed. For ortho-substituted connections, the angles of flat surfaces rotation of benzene rings have been defined