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Vol 95, No 1-2 (2025)
Articles
Synthesis and Antioxidant Activity of Alkyl N-(9H-Thioxanthen-9-yl)(cyclo)alkylhydrazides
Abstract
A series of new alkyl N-(9H-thioxanthen-9-yl)(cyclo)alkylhydrazides was obtained for the first time by the reaction of (cyclo)alkylhydrazides, 9H-thioxanthen-9-ol and pyridinium perchlorate in a pyridine medium. The antioxidant activity of alkyl N-(9H-thioxanthen-9-yl)(cyclo)alkylhydrazides was studied. The greatest antioxidant effect was revealed in linear and cyclic N-(9H-thioxanthen-9-yl)(cyclo)alkylhydrazides, the values of which are in the range of 0.72–0.88 from ascorbic acid. The presence of a branched radical in N-(9H-thioxanthen-9-yl)alkylhydrazides significantly reduces the antioxidant properties.
2-9
One-Pot Four-Component Synthesis of Substituted N-Methyl 5-Охо-1,4,5,6,7,8-hexahydroquinoline-3-carboxamides. Biological Activity of the Obtained Compounds
Abstract
A one-pot four-component solvent-free reaction of N-methyl acetoacetamide with dimedone, aromatic aldehyde and ammonium acetate leads to new substituted N-methyl 1,4,5,6,7,8-hexahydroquinoline-3-carboxamides. The structures of the products were proved using IR, 1H and 13C NMR spectroscopy. The synthesized compounds were tested for antimicrobial and antinociceptive activities. The resulting compounds have shown antinociceptive activity greater than that of metamizole sodium.
10-16
Quantum-Chemical Study of Catalysis in the Reaction of N,O-Dimethyl Carbamate with Methylamine
Abstract
Non-catalytic and sodium acetate and sodium methoxide catalyzed reactions of N,O-dimethyl carbamate with methylamine were studied using quantum-chemical hybrid density functional methods M06 and B3LYP. All interactions proceed through concerted cyclic transition states. Non-catalytic and sodium acetate-catalyzed reactions are characterized by a large activation free energy barrier. The transformation catalyzed by sodium methoxide is characterized by a negative enthalpy of activation and a low free energy of activation.
17-26
Formation of Mass Spectra of Positive and Negative Ions of Trinitrotoluene Isomers under the Gas Chromatography Mass Spectrometry Conditions
Abstract
For the six isomers of trinitrotoluene the processes of chromatographic separation and formation of mass spectra of positive and negative ions have been studied by means of gas chromatography/mass spectrometry (GC-MS). The mass spectra of positive ions were obtained under the standard electron ionization mode at 70 eV. The resonant electron capture negative ionization mass spectra were obtained in the regime of continuous rapid variation of electron energy in the low-energy range 0–10 eV. Analysis of the ionic composition of the positive ionization mass spectra showed that the most fragmentary ions originate from the migration of the methyl hydrogen atom toward an adjacent nitro group causing the formation of [M – OH]+ ions. Negative ions formation, in contrast, proceeds predominantly via nitro-nitrite rearrangements followed by removal of NO- and/or NO2-groups.
27-43
Halogenzincate Pyridinium Ionic Liquids as Precursors for the Synthesis of Zinc Sulfide Nanoparticles
Abstract
Zinc sulfide nanoparticles, quantum dots, were synthesized from halogenzincate 1-alkylpyridinium ionic liquids with different alkyl chain lengths in the cation. The average sizes of zinc sulfide nanoparticles were determined by UV spectroscopy, X-ray diffraction, atomic force microscopy, and scanning electron microscopy. The effect of the structure of halogenzincate 1-alkylpyridinium ionic liquids on the size of zinc sulfide nanoparticles was studied.
44-51
Effect of the Counterion of Styrenesulfonic and Maleic Acid Copolymer on the Properties of Its Complexes with Polyvinyl Alcohol
Abstract
In this work, the interaction of a copolymer of styrene sulfonic and maleic acids in acidic and salt forms with polyvinyl alcohol in a wide concentration range was studied using light scattering and viscometry methods, and it was shown that the nature of the copolymer counterion has a significant effect on the properties of the resulting interpolymer complexes. In dilute solutions, polyvinyl alcohol interacts only with the salt form of the copolymer. In semi-dilute solutions, both forms of the copolymer interact with polyvinyl alcohol, but water-soluble complexes for all ratios of the copolymer and polyvinyl alcohol are formed only with the participation of the acid form of the copolymer.
52-64
Migration Properties and Structure of Phosphate Glasses Containing Alkali Metal Sulfates
Abstract
The paper investigates a set of physico-chemical properties of glasses of the M2O–MPO3, M2SO4–MPO3 (M = Li, Na) systems and glasses of the same systems in which one alkali metal was replaced by another. All compositions were obtained using mortar technology in the manufacture of the initial charge. It was found that almost all the properties of the studied glasses differ slightly in their characteristics from the properties of glasses of similar compositions obtained using solid starting components. It is shown that the electrical properties of pure phosphate and phosphate-sulfate glasses with a commensurate volume concentration of the main current carriers, alkaline cations, are close, i. e. the presence of sulfate ions in mixed glass increases the electrical parameters insignificantly. The equivalent substitution of lithium cations for sodium cations in phosphate and phosphate-sulfate glasses is accompanied by a polychelic effect – a nonlinear change in electrical parameters, and in the phosphate-sulfate system (with a close volume concentration of current carrier ions) this effect is more pronounced.
65-78