Vol 94, No 5 (2024)

A series of previously unknown 4-(het)aryl-6-methyl-2-cyanoimino-N,N-diethyl-1,2,3,4-tetrahydropyrimidine-5-carboxamides was synthesized by the reaction of N,N-diethyl-3-oxobutanamide with (het)arylaldehydes and N-cyanoguanidine. The structure of the obtained compounds was established by IR, ¹H NMR spectroscopy and single crystal X-ray diffraction analysis.

(E)-1-(4-Pentyloxyphenyl)-3-(aryl)prop-2-en-1-ones were obtained by condensation of 1-(4-pentyloxyphenyl)ethanone with aromatic aldehydes in an aqueous ethanol solution in the presence of NaOH. The corresponding pyrazoline derivatives were prepared by cyclization of substituted chalcones with phenylhydrazine in an acidic medium, while 2,4,6-triaryl-substituted pyrimidines were produced in the case of benzamidine hydrochloride in the KOH–ethanol. It was found that all synthesized pyrazoline derivatives exhibit pronounced luminescent properties. A docking study of the compounds was carried out against four types of receptors.

The reaction of substituted 1-aminoalkyl-3-hydroxy-3-pyrrolin-2-ones with hydrazine hydrate in boiling glacial acetic acid leads to the formation of 1-aminoalkyl-5,6-diaryl-2-oxopyrrolo[3,4-c]pyrazoles. The structure of the obtained compounds was confirmed by IR, ¹³C NMR and ¹H NMR spectroscopy methods.

The synthesis of a phosphinic structural analogue of the tetrapeptide Met-Glu-γ-His-Phe by adding the dipeptide component His-Phe to the adamantyl ester of the phosphinic pseudo-Met-[P]-Glu-peptide in the form of cyclic glutamate anhydride is proposed. The conditions for the interaction of phosphinic pseudo-Met-[P]-Glu-anhydride with His-Phe in free form to form phosphinic Met-[P]-Glu-γ-His-Phe tetrapeptide have been found. A chromatographic mass-spectrometry study, including MS2, and NMR of the phosphinic tetrapeptide on ¹H, ¹³C, ³¹P nuclei was carried out using the methods of two-dimensional ¹H–¹H COSY, ¹H–¹³C HSQC and ¹H–¹³C HMBC NMR spectroscopy.

Palladium(II) extraction from hydrochloric acid solutions with 2,6-bis[(methylsulfanyl)methyl]cyclohexan-1-one, obtained from natural methanethiol, was studied using chloroform as a diluent. Palladium(II) is recovered rapidly and with high efficiency by the extractant from solutions of 0.1–10 mol/L HCl and can be separated with high selectivity from Pt(IV), Cu(II), Ni(II), Zn(II) and Fe(III). A coordination mechanism of the palladium(II) extraction from 1 M HCl solutions was established. The extraction agent is coordinated to the Pd(II) ion through donor sulfur atoms in an extracted compound of the [PdCl₂L] type. Stripping of Pd(II) is effectively carried out with a 1 M NH₄OH solution or an acidic (0.1 mol/L HCl) thiourea solution.

The thermodynamic features and mechanism of the electrocatalytic oxygen reduction reaction were studied using the revPBE0-D3(BJ)/Def2-TZVP method on the example of (6,6)-armchair carbon nanotube doped with a tricoordinated silicon atom and nitrogen atoms of pyridinic and graphitic nature. Irreversible oxidation of the silicon center as a result of the formation of stable oxygen-containing adsorbates was shown. It was found that Si-poisoned structures are capable of participating in the catalysis of the target reaction along two- and four-electron routes at high overpotentials. For a nanotube doped simultaneously with pyridinic and graphitic nitrogens the potential possibility of eliminating the silicon atom from the catalyst composition in the form of orthosilicic acid and the participation of a silicon-free nitrogen-doped framework in the oxygen electroreduction reaction, for which the stage of tautomerization of pyridin-2(1H)-one to pyridin-2-ol is the limiting step was shown.