Voprosy khimii i khimicheskoi tekhnologii (Issues of Chemistry and Chemical Technology)

5-15

Authors: S.M. Varvarenko, M.V. Ferens, V.Ya. Samaryk, N.G. Nosova, N.V. Fihurka, D.D. Ostapiv, S.A. Voronov

The copolyesters containing fluorescein as a repeating link have been synthesized via low-temperature copolycondensation with 2-(dodecanamino) pentanedionic acid for the first time. The factors are determined that allows using fluorescein as a hydroxyl-containing monomer in the reaction of activated polycondensation during the synthesis of copolyesters in a solution. The features of the interaction between N-substituted amino acids and fluorescein via Steglich reaction have been established based on the obtained results. It was stated that such solvents as methylene chloride or benzene promote a low yield of copolyesters. This is caused by the rearrangement of the activated carboxylic acid group of 2-(dodecanamino) pentanedionic acid with the formation of non-reactive terminal fragments in oligomeric molecules, which are not capable of further polycondensation. Using a mixture of solvents (benzene and dimethylformamide) allows suppressing the rearrangement reaction and obtaining copolyesters, which are characterized by functional homogeneity, with a high yield. The synthesis of copolyesters of 2-(dodecanamino) pentanedionic acid and fluorescein confirms the possibility to use fluorescein as a comonomer in activated copolycondensation via Steglich reaction. Such synthetic approach allows obtaining new polymers containing chromophore groups in the main macromolecular chain.

24-29

Authors: A.I. Karkhut, S.V. Polovkovych, M.S. Kurka, L.R. Zhurakhivska, V.P. Novikov

Diels-Alder reaction of anthracene and its derivatives with various dienes are of great interest as it is used in many branches of chemistry: from synthesis of biologically active substances to dendrimers extension. In this study, we considered a rapid irreversible Diels-Alder reaction between anthracene and azo-bis-cyanuric chloride as active electron-deficient diene which can be easily functionalized. The investigation was performed experimentally and on M06-2X/6-31+G(d,p) level. It was found that the reaction proceeds through the formation of intermediate colored charge transfer complex which is rapidly exhausted. The reaction was found to be synchronic with symmetric transition state and charge transfer ratio about 0.56 electron. The conditions of a further modification of the product by chlorine atoms substitution were also determined. It rapidly decomposes in strong acidic medium but is stabile thermally and in alkaline conditions, which makes it possible to modify it further by different nucleophiles. The O- and N-substituted compounds were obtained via the reaction of Diels-Alder reaction product with sodium alcoholates at room temperature and with secondary amines at 90C in the presence of triethylamine, respectively. The structure of products was confirmed by 1H and 13C NMR spectroscopy. The charge transfer bands of intermediate complex were characterized by UV-Vis spectroscopy.

39-45

Authors: A.V. Slipkan, D.E. Kytova, A.V. Shtemenko

Zirconium phosphate nanoparticles loaded with trichlorotri-μ-carboxylates of dirhenium(III) of the general formula Re2(RCOO)3Cl3 (where R=C2H5, C3H7, i-C3H7) were synthesized. The intercalation process was carried out in an acetonitrile medium. The obtained nanoparticles with the loading of dirhenium(III) complex in the substance/ZrP ratio 1:5 and 1:30 were analyzed by electron and IR-spectroscopies, X-ray powder diffraction and gravimetric analysis. The behavior of the complex compound in the selected solvent was also studied and it was confirmed that the transformations, which the complex compound undergoes as a result of the intercalation process, are not related to the influence of the medium. The diffraction patterns of the samples of both ratios indicate an increase in the interlayer distance of zirconium phosphate from 7.6 Å to 12.1 Å, which shows the successful intercalation of dirhenium(III) compound in the layers of the inorganic matrix. Taking into account the data of all the analysis methods used, it can be considered that the reaction occurs with the formation of a cis-structural compound with two phosphate and two carboxylate groups in the equatorial position and with acetonitrile in the axial position. The release rate of the substance in an acid medium simulating the tumor cell environment was 2 hours and 45 minutes.

51-59

Authors: Yu.A. Chertihinа, O.S. Lebed, N.V. Kutsik-Savchenko, A.S. Lib, A.V. Tsyigankov, A.V. Prosyanik

The energy and electronic parameters of the nitrogen inversion in the amines H2NXHn (XHn = CH3, NH2, OH, F, SiH3, PH2, SH, and Cl) have been calculated using DFT (PBE96/def2-tzvpp) method. It has been established that the inversion barriers of the amines containing elements of the second or third period at the nitrogen atom (with the exception of C and Cl) correlate with the - and і-constants of the XHn substituents and increase with an increase in electronegativity of the substituents. Intramolecular interactions have a secondary influence on the inversion barriers; they promote an increase in the inversion barriers of the amines containing elements of the second period (except for F) and a decrease in the inversion barriers of the amines containing elements of the third period (except for Cl) with increasing the electronegativity of XHn substituents along the period. The donor-acceptor interactions of the lone pairs of the nitrogen atom and heteroatom X with the antibonding orbitals of X–H and N–H bonds make a main contribution to a decrease in the inversion barriers, these interactions increasing commonly in the transition states of inversion. The repulsive interactions of the nitrogen lone pair with orbitals of nitrogen -bonds or the lone pairs of heteroatom X, on the contrary, contribute to an increase in the inversion barriers. The interactions between the lone pairs of nitrogen and chlorine atoms make a dominating contribution to the abnormally high value of the inversion barrier of chloramine. The observed energies of the interactions between nitrogen lone pair and Rydberg orbitals of heteroatoms (including the nN3dS interactions) disprove the significant and, especially, dominant contribution of these interactions to a decrease in the inversion barriers of amines containing heteroatoms of the third period in comparison with amines containing heteroatoms of the second period of the same group. Small inversion barriers of the corresponding amines are mainly due to the low electronegativity of the XHn substituents (with the exception of Cl).

70-78

Authors: S.O. Kyrii, I.V. Kosogina, I.M. Astrelin, L.S. Obodenko

The modification of the surface of activated carbon by the products of acid treatment of "red mud" was investigated in this work. It was established that the active components of "red mud" get inside the pores of carbon when the modification of the activated carbon of F300 brand is performed by the impregnation method, whereas these components are fixed on its surface when the modification is carried out by the method of thermal-acidic activation. The structurally-sorption characteristics of the obtained sorption materials were established. The electrokinetic potentials (zeta potentials) of adsorbents and adsorbate in a wide range of pH of the aqueous medium were determined. To determine the adsorption efficiency, the concentration of natural organic matter was investigated by means of spectrophotometric method before and after adsorption. A high degree of the removal of sodium salt of humic acid was stated, it reaches 98% for the sorption material SM1 at a dose of 4 g L-1 and 95% for the sorption material SM2 at a dose of 6 g L-1.

86-94

Authors: G.S. Pop, O.I. Safronov, I.S. Bodachivskyi, L.V. Zheleznyi

A number of surface-active alkylolamides are synthesized by the chemical transformation of oils and phosphatides, the composition and structure of them were established by spectral and colloid-chemical methods. It is shown that the solutions of synthesized substances in petroleum oil are characterized by improved adhesion and anticorrosive properties. These solutions meet the high ecological and economic current requirements and can be used to create the compositions of conservative oils, greases, protective technological systems in agricultural machinery, main pipelines, oilfield and oil refining equipment as well as in chemical, petrochemical, oil and gas producing industries. Hydrocarbon solutions of the products resulted from the condensation of ethoxylated ethylene diamine with rapeseed oil and phosphate concentrate formed in its purification show emulsifying and stabilizing properties in invert technological systems designed to intensify mining and overhaul of oil and gas wells. It is stated that the most acceptable product of phosphatides transformation (with respect to the availability of raw materials and technological efficiency) is able to improve the tribological, antioxidant and protective properties of various grades of lubricants. It is recommended as an active addition to various types of oils as well as to antifriction greases designed to lubricate rolling bearings, slides and other friction units of industrial equipment, which are operated in a wide temperature range under high load conditions and in aggressive environments.

101-108

Authors: V. Skorokhoda, N. Semenyuk, І. Dziaman, Kh. Levytska, G. Dudok

The paper is devoted to the study of the preparation of osteoplastic porous composites based on 2-hydroxyethyl methacrylate copolymers with polyvinylpyrrolidone filled with mineral calcium fillers. The study of the polymerization kinetics of compositions of 2-hydroxyethyl methacrylate with polyvinylpyrrolidone in the presence of fillers of various natures was performed. It was revealed that the composites containing montmorillonite and wollastonite as fillers show the highest reactivity; this indicates an active participation of these fillers in the reaction of the preparation of polymeric composites. An active influence of the nature and quantity of a filler on the parameters of grafting, the composition of copolymers and the properties of composites on their basis was established. In the case of the use of montmorillonite as a filler at a temperature of 348 K, considerably more polyvinylpyrrolidone (almost 98%) enters into the grafting reaction than in the case of wollastonite (74%) and hydroxyapatite (58%), which indirectly confirms an active participation of montmorillonite in the initiation of polymerization. In the case of hydroxyapatite, both the efficacy and the degree of grafting decrease with an increase in its content in the composition. The use of ultrasound treatment significantly intensifies the process of the preparation of porous composites. The developed composites can be used in medicine for the replacement of damaged bone tissue.

115-121

Authors: K.V. Stashenko, T.V. Rudenchyk, R.A. Rozhnova, T.O. Kiselova

A number of polyurethane ureas (PUU) were synthesized which contain in their structure the fragments of copolymer of N-vinylpyrrolidone with vinyl alcohol (VP–VA) and with a 1,6-hexamethylenediamine (GMDA) at different percentage ratio of GMDA to VP–VA (30:70, 50 50 and 70:30). Based on synthesized PUU, some composite materials with lysozyme were obtained, the content of the drug substance being 1 wt.%. According to the results of IR-spectroscopic study, the immobilization of lysozyme occurs due to intermolecular hydrogen bonds (the so-called physical immobilization). It was established that the samples of PUU with fragments of VP–VA in their structure filled with lysozyme and synthesized at a percentage of HMDA to the copolymer VP–VA of 70:30 have better physical and mechanical properties in the series (σ = 23.7 MPa and ε = 217%). The introduction of lysozyme into the composition of the obtained polymeric materials results in an increase in the strength at break in comparison with the unfilled samples (179% and 47%, respectively). As the concentration of the VP–VA copolymer increases, the glass transition temperature and the heat capacity jump increase. It was found that the systems under consideration are single-phase.

128-136

Authors: O.S. Shulga, N.V. Simurova, S.I. Shulga, O.P. Perepelytsya

The article presents the results of the modification of potato starch by propionic acid chloroanhydride and the physical and chemical characteristics of the resulting product. Based on the analysis of published data, the modification method was suggested in which dimethyl sulfoxide (DMSO) is used. The chosen solvent is widely used in organic synthesis since it is completely soluble in water, therefore its residues can be completely removed after the reaction. In addition, DMSO is low-toxic, it is used as a drug in pharmaceutical industry. Propionic acid was selected as a modifier, because it is widely used in food industry as a food additive E 280. The modified starch is intended for the further application in food industry; that is why the aforesaid reagents have been selected. The degree of substitution in starch molecule was determined by means of NMR analysis and elemental analysis, it proved to be 1:1. There is a band at 1731.46 cm-1 in the IR spectrum of modified starch, this band is characteristic of C=O in the ester group. The X-ray diffraction analysis of native and modified starches showed that acylation leads to a decrease in crystalline phase from 12% to 2%. The microscopic study revealed that the modification of potato starch by propionic acid chloroanhydride changes the size and shape of starch grains. The thermal analysis showed that the thermogravimetric curve of the modified potato starch is more complicated than that of native potato starch which is explained by the change in the chemical structure.