Том 87, № 6 (2017)

DFT calculations (M06, PBE0/Def2-TZVP) of coordination compounds used in reactions of selective oxidation of thiols to disulfides were performed. Primary active centers of the catalysts are polynuclear scaffolds {L₂M(μ-OH)₂ML₂}²⁺ and {L₂M(μ-OH)₂M′(μ-OH)₂ML₂}²⁺ (M = Cu^I, Cu^II, Pd^II; M' = Cu^II; L = NH₃). Cu^II ions in combination with PdII ions are capable of formation of polynuclear active center {PdII(μ-OH)₂Cu^II(μ-OH)₂Pd^II}²⁺ bringing together a large number of mutually oriented RS^– groups and thus affecting the rate of formation of disulfide R₂S₂.

Quantum-chemical simulation of the ground state [the density function B3LYP/6-31G, B3LYP/6-31G(d), and B3LYP/6-31+G(d,p) and the perturbation theory MP2/6-31G(d) methods] and the transition states [the B3LYP/6-31G(d) method] of 4,4′-methoxypropylstilbene molecule has been performed. Using the Ellinger MM2 force field method, the potentials of internal rotation have been obtained for each rotational degree of freedom of the molecule. The B3LYP simulation has revealed the planarity of the conjugated system and the orthogonal position of the alkyl substituent, whereas the benzene rings have deviated by about 20° with respect to the double bond plane according to the MP2 data. Three transition states of the molecule corresponding to the saddle points of the first and the second orders have been revealed. The stationary points have been identified by means of vibrational analysis.

Main products of the reaction of vinyltrichlorosilane VinSiCl₃ with DMSO in the medium of tetra-(alkoxy)silane are linear siloxanes (RO)₃Si[OSiVin(OR)]OSi(OR)₃, RO[Vin(RO)SiO]_nSi(OR)₃ (R = Me, Et, n = 0–2) and the hitherto unknown cyclic siloxanes [Vin(RO)SiO]_m[(RO)₂SiO]_4–m (m = 1–3) formed in the ratio of 70: 30%. A tentative scheme of their formation is suggested with participation of the products of the alkoxy groups exchange between vinyl(alkoxy)dichloro-, vinyldi(alkoxy)chloro-, trialkoxychloro-, and dialkoxydichlorosilanes.

By an example of butanethiol the addition of mercaptanes in the presence of bases to alkyl 3-furyl-3-(diethoxyphosphoryl)acrylic acids having methyl, methoxymethyl, or diethoxyphosphorylmethyl substituent in the furan ring was studied. It was shown that in the majority of cases alkyl 2-(butylthio)propionate was the main product, and 3-(butylthio)propionate was the minor one. Ethyl 3-(4-methylfur-3-yl)-3-(diethoxyphosphoryl) acrylate affords these two substances in equal quantities. In the case of ethyl 3-(4-methoxymethyl-5-methylfur-2-yl)-3-(diethoxyphosphoryl)acrylate only 3-(butylthio)propionate is formed.

Conjugates of ferrocene and 4,5-dichloroisothiazole were synthesized, where the ferrocene and isothiazole moieties are linked through various structural fragments. The acylation of ferrocene with 4,5- dichloroisothiazole-3-carbonyl chloride gave (4,5-dichloroisothiazol-3-yl) ferrocenyl ketone; the acylation of aminomethylferrocene furnished the corresponding amide. The esterification of ferrocene-1,1′-dicarboxylic acid with 4,5-dichloroisothiazol-3-yl-methanol resulted in the formation of the corresponding ester. The condensation of 1,1′-diacetylferrocene with 4,5-dichloroisothiazole-3-carbaldehyde afforded ferrocenophane containing 4,5-dichloroisothiazole moieties.

The complex formation of β-octaethylporphyrin, β-octaethyl-meso-monophenylporphyrin, β-octaethyl-meso-tetraphenylporphyrin, meso-diphenylporphyrin, meso-triphenylporphyrin, and meso-tetraphenylporphyrin with Zn(II), Cu(II), Co(II), and Mn(II) acetates and chlorides in dimethylformamide, dimethylsulfoxide, pyridine, acetic acid, and a chloroform–methanol 1 : 1 mixture has been studied by means of spectrophotometry. The observed regulations are in line with the concept of chemical reactivity of the N–H bonds in porphyrins of different complexity.

New ionic binuclear complexes of iridium(III) containing 1,4-bis[2-(2-pyridyl)benzimidazolato]butane as a bridging ligand were synthesized. These compounds exhibit intensive photo- and electroluminescence of yellow-green, green-yellow, and pink colors. The maximal electroluminescence brightness was 4565 cd/m².

Mechanical activation of the natural biopolymer arabinogalactan with organic acids (succinic, aminoacetic) was studied by IR spectroscopy and X-ray phase analysis. Evidence was obtained for the formation of mechanocomposites with a chemical bond between the natural biopolymer and organic acids. The nature of this bond depends on the nature of the acid. The composites obtained by mechanical activation of such mixtures are stable disperse systems with a uniformly distributed active ingrediaent.

Sorption of methyl violet from an aqueous solution by a perfluorosulfonic membrane is accompanied by the indicator protonation. Changes in the absorption spectra of the indicator and the corresponding color transitions, which are consistent with the shape of the isotherm of water adsorption by the membrane, characterize it as a strong solid acid.

Synthesis of new fused systems of triazino[5,6-b]indole starting with preparation of 3-amino[1,2,4]-triazino[5,6-b]indole 1 by reaction of isatin with 2-aminoguanidinium carbonate in boiling acetic acid is presented [1]. Intermediate compound 1 reacted with aldehyde, ethyl chloroformate, triethyl orthoformate, and ninhydrine and gave new heterotetracyclic nitrogen systems, such as 3-(N²-guanidinylimino)indole-2(1H)-one 2, 3-(N-ethoxycarbonylamino)-4H-[1,2,4]triazino[5,6-b]indole 3, 3-(N-ethoxymethyleneamino)-4H-[1,2,4]-triazino[5,6-b]indole 4, 3-(hydrazinothiocarbonylamino)-4H-[1,2,4]triazino[5,6-b]indole 5, respectively. N-(1,3-dioxoindene-2-ylidene)-4H-[1,2,4]triazino[5,6-b]indol-3-amine 6 was synthesized by reaction of compound 1 with aldehyde, ethyl chloroformate, triethyl orthoformate, and ninhydrine. New fused indole systems, pyrimido[2′,1′:3,4][1,2,4]triazino[5,6-b]indol-3(4H)-one 8, 9, 11, 12 and 1H-imidazo[2′,1′:3,4][1,2,4]triazino-[5,6-b]indol-2(3H)-one 10, were synthesized in the reaction of the intermediate 1 with bifunctional compounds. Structures of the products were elucidated from their elemental analysis and spectral data (IR, ¹H and ¹³C NMR and mass spectra). Antimicrobial activity of some synthesized compounds was tested.

A series of substituted and fused heterocyclic derivatives 2–17 were synthesized using 3,5-bis(4-methoxybenzylidene)-1-propylpiperidin-4-one (1) as starting material. Treatment of 1 with malononitrile or semicarbazide afforded compounds 2 and 3, respectively. Condensation of 1 with ethyl cyanoacetate afforded naphthyridine-3-carbonitrile derivative 4, which reacted with phosphorus pentachloride and phosphoryl chloride to give chloro derivative 5. Treatment of 5 with thiosemicarbazide afforded compound 6. The reaction of 1 with malononitrile gave cyano aminopyrane derivative 7 which was condensed with pyromellitic dianhydride, phthalic anhydride, succinic anhydride, or morpholine in glacial acetic acid to obtain imide derivatives 8–11. Additionally, the reaction of 7 with aromatic aldehydes gave derivatives 12a–12c. Acetylation of 7 with acetic anhydride in boiling acetic acid gave N-acetyl derivative 13 which was cyclized to pyridine derivative 14 by refluxing in dioxane in the presence of triethylamine. Treatment of 7 with hydrazine hydrate gave pyrazolo derivative 15. Finally, the reaction of 7 with triethyl orthoformate in the presence of acetic anhydride gave formimidate 16 which was treated with hydrazine hydrate to form N-amino derivative 17. Some of the synthesized compounds were examined in vitro for their antitumor activity against HepG-2, PC-3, and HCT-116 human carcinoma cell lines using MTT assay.

Biologically active triazole derived Schiff bases, 2-methoxy-6-[(Z)-(1H-1,2,4-triazol-3-ylimino) methyl]phenol (L₁) and 4-[(Z)-(1H-1,2,4-triazol-3-ylimino)methyl]benzene-1,3-diol (L₂) were prepared by condensing 3-amino-1,2,4-triazole with 2-hydroxy-3-methoxybenzaldehyde and 2,4-dihydroxybenzaldehyde in the 1 : 1 molar ratio. Structures of the synthesized ligands were characterized by IR, NMR and Mass spectral data. The ligands were complexed with the ions of V, Cr, Mn, Fe, Co, Ni, Cu, and Zn to form the complexes M : L in the 1 : 2 molar ratio. The synthesized Schiff bases potentially behaved as tridentate ligands and coordinated to metal ions via azomethine-N, triazole-N, and benzaldehyde-O. Structure elucidation of complexes involved IR, UV-Vis, MS, and molar conductance data. These compounds were tested for antibacterial activity against Halomonas halophila, Chromohalobacter israelensis, Chromohalobacter salexigens, Staphylococcus aureus, Halomonas salina, and Neisseria gonorrhoeae bacterial stains. Antifungal activity of the synthesized compounds was studied by using different fungal stains like Trichophyton Longifusus, Candida Albicans, Aspergillus Flavus, Microsporum Canis, Fusarium, Solani, and Candida Glabrata. All synthesized compounds displayed high antimicrobial activity against one or more strains.

1-(3-Chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazole-4-carbaldehyde was used in preparation of (E)-1-{[1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazol-4-yl]methylene}thiosemicarbazide. Its following reaction with ethyl bromoacetate, diethyl 2-bromomalonate, phenacyl bromide, and maleic anhydride gave pyrazolyl pharmacophore linked thiazole, thiazoline and thiazolidinone-5-carboxylic acid derivatives.

Reactions of 3,5-di-tert-butyl-4-hydroxybenzyl acetate and dimethyl [(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadienylidene)methyl]phosphonate with 5,7-dimethyl-1,8-naphthyridin-2-amine and 7-amino-2,4-dimethylquinoline were studied. New derivatives of sterically hindered phenols based on heteroaromatic scaffolds were obtained.

An efficient one-pot method for the synthesis of 5-alkylsulfanyl-1H-tetrazoles, tetrazol-5-ylmethane- and -ethanethiol derivatives was developed.

Intramolecular cyclization of 5-methyl-4-(3-phenylprop-2-yn-1-yl)-4H-1,2,4-triazole-3-thiol led to the formation of 7-benzylidene-3-methyl-6,7-dihydro-5H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine.

Production of high-strength fibers from flexible-chain polymers having mechanical properties close to theoretically possible is one of the most important problems of physical chemistry and technology of polymers. Essential progress in this field has been achieved with the advent of gel spinning. Further enhancement of the mechanical properties of flexible chain polymers is possible only by complex investigations and, on their basis, goal-oriented formation of an optimal gel structure at all stages of the technological process. In this paper the structural transitions in ultrahigh-molecular-weight polyethylene (UHMWPE) in the course of gel spinning of high strength fibers were studied by optical spectroscopy, electron microscopy, X-ray diffraction, and differential scanning calorimetry. Special attention was devoted to such important stages of the gel spinning process as the liquid‒gel transition and the transition of gel fibers into a highly oriented state. It was shown that the structure of thermoreversible UHMWPE gels can described in terms of a modified Keller model. According to this model, the nodes of the spatial gel network are lamellar microcrystallites 4-5 nm in thickness and 20 nm in lateral dimension. During orientation drawing of UHMWPE gel fibers, gradual straightening of molecular folds occurs, and the structure comprising crystallites on folded chains transforms to the structure composition fibrillar crystallites on straight chains. Investigation on a solvent-free technology of fabrication of high-strength film fibers from UHMWPE reactor powders (RPs) was initiated. The technology includes three stages: RP consolidation (compaction), fabrication of a monolithic film (monolithization), and orientation drawing of the monolithic film. A special cell for consolidation and monolithization is was developed. The effect of temperature and applied pressure on the consolidation and monolithization of the UHMWPE RP was studied. It was found that at ambient temperature and a pressure of 136 MPa the consolidation process is complete within 15 min. The optimal temperature range for the monolithization process is 135–140°С. First results of attempted orientation drawing of UHMWPE monolithic films are reported.

The interest in bio-based and biodegradable products has increased recently, following the depletion of fossil fuels and aggravation of environmental problems all over the world. Replacement of nondegradable synthetic polymers by biodegradable polymers brings about a 10–20% per year expansion to the market of environmentally pure and friendly composites and materials. A lot of researchers take part in studies on biodegradable polymers. According to their synthesis route, structure, properties, and application areas, biodegradable polymers are classified into agro-polymers (including cellulose, starch, chitin, and protein) and biodegradable polyesters: poly(lactic acid), poly(hydroxyalkanoates). So-called biopolyesters were synthesized from fossil fuel resources, but the modern trend is towards obtaining the main products from renewable resources.

Approaches to modifying synthetic fibrous materials through the use of nanosized fillers in the preparation of thermoplastic filaments from melt were considered. Examples of new ways to improve the performance characteristics and impact new features (high strength, low electrical resistance, biocidicity, etc.) to synthetic materials via their bulk modification were given.

Systematic analysis of the effect of various factors on the behavior of polymer solutions used for forming the porous structure by impregnation of nonwoven fibrous substrates in the process of fabrication of synthetic composite materials and coatings is performed. Scientific foundations of a targeted control of the phase separation of polymer solutions on their modification with interpolymer complexes of different compositions and structures in order to obtain products and materials with a porous structure and set of performance characteristics required for various applications.

A method was proposed for modification of cellulose and polyester textile materials with monoand heterometallic copper and/or silver sols for imparting the ability to affect microorganisms to textile matrices. Data were presented on the dynamics and features of the reduction of copper and silver cations in the presence of phosphonic acid derivatives and/or natural macromolecular compounds as chelators. The stable monometallic and mixed particles synthesized were shown to be effective in imparting antimicrobial activity to natural and synthetic fibers (through the example of Candida albicans fungus) and in protecting them against biodegradation by soil microflora and natural complex microflora.

Methods for synthesis and production of FIBAN ion exchange fibers, which are based on the radiation chemical and chemical modification of polypropylene and polyacrylonitrile fibers were developed. The possible applications of FIBAN materials for water and air purification from harmful impurities, separation of valuable products from the liquid media, and catalysis are considered.

Textile auxiliaries of different chemical types were tried in fiber finishing application for polyester, woolen, and blended textile materials. All the tested chemicals were produced in the Russian Federation. Investigation covered the influence of the chemicals on the antistatic, frictional, and deformational properties and mechanical strength of the textile materials. The most effective products were selected, whose application in the fiber finishing process makes it possible to improve the physicochemical properties of textile materials: decrease the fiber‒metal dynamic friction coefficient by 15‒20%, increase the tensile strength of the fibers by 8‒10%, and increase the electric conductivity of the textile material.