Russian Chemical Bulletin最新文献

A new bismuth complex with the N-(5,6-dihydro-4H-1,3-thiazin-2-yl)benzamide ligand (L = C₁₁H₁₃N₂OS) was synthesized for further medical use. The complex and the ligand exhibit anticancer activity. The structure of the complex was characterized by NMR spectroscopy, inductively coupled plasma atomic emission spectroscopy (ICP-AES), and laser-induced electron transfer desorption/ionization (LETDI) mass spectrometry. The Bi: L ratio is 1: 1; the components are connected by an ionic (ion-dipole) interaction. The reaction of bismuth(iii) chloride with ligand hydrobromide (L•HBr) affords the complex {(C₁₁H₁₃N₂OS)₃[Bi₂Cl₉]}. The composition of this complex was confirmed by X-ray diffraction, ICP-AES, and LETDI methods.

Synthesis of N-substituted 4-aryl-2-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-ylamino)-4-oxobut-2-enamides by the reaction of the substituted 2-[(5-aryl-2-oxofuran-3(2H)-ylidene)amino]-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitriles with primary amines was developed. Anti-inflammatory activity and acute toxicity of the synthesized compounds were examined. It was found that the synthesized compounds possess pronounced anti-inflammatory activity and low toxicity. According to the classification of toxicity of drugs, the synthesized amides belong to toxicity class V of practically nontoxic substances.

A molecular docking study aimed at shedding light on the binding mechanisms of a nitrosyl iron complex to bovine serum albumin (BSA) revealed three possible binding sites. Main types of bonds were established. The complex—BSA binding energies at different sites were determined using the AutoDockTools program and from QTAIM analysis. Docking with inclusion of water molecules led to shielding of one binding site (only two binding sites remain) and to a better agreement between the binding energies obtained by two different methods. Electronic spectra of the resulting molecular complexes were simulated in terms of the time-dependent density functional theory (TDDFT). The changes in the experimental spectrum as well as stabilization of the nitrosyl iron complexes by BSA were explained.

Azide-tetrazole tautomerism in a series of substituted 2-azidopyrimidines were studied by NMR spectroscopy methods. The structures of the tautomers existing in a solution were determined. By varying the temperature, the activation parameters of the studied tautomerism were determined from the integrated signal intensity in the NOESY/EXSY spectra. It was found that the phenyl substituents accelerate the tautomeric transformations.

The colloidal-chemical properties of oxyethylated polypropylene glycols (pluronics), soluble and slightly soluble in water and containing a hydrophobic polypropylene glycol block with the same length but with different degrees of oxyethylation, were analyzed. It was determined that both pluronics are characterized by high surfactant properties, making it possible to use them as surfactants in heterophase polymerization processes. The observed differences in the kinetic specific features of the polymerization of styrene and methyl methacrylate (average particle diameter and polymerization rate, the character of the monomer conversion—time curves) allowed us to infer that the formation of the polymer-monomer particles occurs by different mechanisms. The obtained results showed that these surfactants are promising for the synthesis of polymer suspensions with a narrow particle size distribution and an average diameter in the range from 0.09 to 1.7 µm.

The literature data on the use of triphenylphosphine in determining peroxide functional groups and individual oxygen-containing compounds in the composition of the products of oxidation reactions of organic compounds with molecular oxygen and/or peroxides were systematized and discussed. The causes and mechanisms of distortions of the results of analytical determinations were identified and possible ways of their elimination were suggested.

Metal-semiconductor bifunctional core-shell nanomaterials were studied using catalytic system Au@CdS as example that displayed surface plasmon resonance (SPR) effects and photocatalytic activity. Some mechanisms of photocatalytic activity of the studied nanomaterials were discussed. Surface-enhanced Raman spectroscopy (SERS) was used to monitor in situ the SPR-driven photocatalytic dimerization of 4-nitrothiophenol (pNTP) to 4,4′-dimercaptoazobenzene (DMAB). The transfer path of “hot” electrons in Au@CdS was tracked by monitoring Raman spectral changes of the probe molecule. Nanomaterials Au@CdS showed high catalytic activity in photocatalytic degradation of rhodamine 6G. The SPR-displaying metal-semiconductor nanocomposite was indicated to be an extremely promising photocatalytic and in-situ SERS probe.

A quantitative study of the composition of metastable acidic tungstate-vanadate solutions was carried out. The main polyanions coexisting in the solutions were determined by means of UV spectroscopy. Effect of the initial V: W ratio on the nature and concentration of polyanions was determined. Electrochemical deposition of hydrated tungsten oxide films from mixed solutions was carried out. The addition of 5–30 mol.% of vanadium leads to a significant increase in the deposition rate, and these rates are higher than in analogous solutions with the addition of H₂O₂. It is shown, that the growth of films in mixed solutions is associated with the formation of the Lindquist polyanions [VW₅O₁₉]³⁻ and [V₂W₄O₁₉]⁴⁻ with high redox potentials. These polyanions are irreversibly destroyed upon reduction. The influence of various polyanions on the film growth was demonstrated in test experiments on the deposition from solutions prepared from individual salts of the polyanions. Films deposited from mixed tungstate-vanadate solutions contain a very low amount of vanadium as it was shown by elemental analysis.

The aerobic oxidation of dibenzothiophene (DBT) was studied in hexadecane under ultrasonic treatment. Under these conditions, aldehydes can activate oxygen; however, the activation efficiency largely depends on the chemical nature of the aldehyde. The time dependence of the DBT oxidation in hexadecane was studied in the presence of valeraldehyde, caprinaldehyde, benzaldehyde, and anisaldehyde. After the treatment, the DBT concentration in hexadecane can decrease from 100 to 6 ppm. In the absence of ultrasonic treatment, the reaction does not proceed under these conditions.

A total of 5233 lanthanide coordination polyhedra of the composition MO₈ were selected from Cambridge Structural Database and analyzed using modern methods of unsupervised learning. The results of geometric clustering were compared with those of the continuous shape measure analysis, which is most widely used for analyzing the coordination polyhedra. The applicability was demonstrated of the new method to classification of the coordination environments that are difficult to analyze using conventional techniques.