Том 68, № 4 (2019)

The review prasents a survey of the synthesis and structures of luminescent transition metal complexes with 2,1,3-benzothiadiazole ligands. Specific noncovalent interactions involving 2,1,3-benzothiadiazole moieties, which have a significant effect on the crystal packing and properties of the complexes, are analyzed.

The review summarizes literature data on various approaches to the synthesis of substituted imidazole-4,5-dicarboxylic acids ranging from assembly from low-molecular-weight components, to modifi cation of the parent structure, and to degradation of more complex molecules.

The review summarizes the results obtained by our research group over the past 15 years in chemistry of N-, S,N-, and Se,N-heterocycles resulted from aminomethlation of a wide range of acyclic and heterocyclic substrates derived from active methylene amides, thioamides, and selenoamides. A series of 1,3,5-thia(selena)diazines, 3,7-diazabicyclo[3.3.1] nonanes, 3,5,7,11-tetraazatricyclo[7.3.1.0^2,7]tridec-2-enes, 1,3,5,7-tetrazocines, and pyrido[1,2-a][1,3,5]triazines were synthesized. The general regularities of the Mannich reaction in the series of N-, S,N-, and Se,N-containing pyridine substrates were discussed. Biological activities of some synthesized compounds were studied to reveal compounds with antiviral, analeptic, anti-inflammatory, and antipyretic activities.

A general problem in the production of the main types of liquid biofuel, bioethanol and biodiesel, is that renewable resources are not utilized completely. These are ballast polyols: hemicellulose or its structural units, pentaatomic monosaccharides (xylose and arabinose), and biodiesel glycerol. The problem of utilization of these compounds by transforming them into a hydrophobized fuel form by the conversion to cyclic ketals (CK) during condensation with lower carbonyl compounds is reviewed. The CK—ethanol pair significantly increases the octane number and provides phase stability of fuel compositions. The ability of CK to inhibit radical processes responsible for fuel characteristics was studied in model reactions with phenyl radicals and atomic chlorine. The carbon-centered radicals formed in protic media are transformed into more stable cyclic radical cations. Alternative methods of processing natural raw materials using biocatalysis and supercritical fluid technologies are analyzed.

A quantum chemical study of the structure, energy, and magnetic characteristics of di nuclear heterometallic complexes constructed via coordination of 5,6-bis(salicylideneimino)-1,10-phenanthroline to the cobalt(II) or copper(II) ions (by the azomethine moiety) and to the iron(II) ion (by the phenanthroline moiety) is carried out using the density functional theory at the DFT UTPSSh/6-311++G(d,p) level. It was shown that all the considered compounds can exhibit thermally-controlled spin-crossover at the iron center. Coordination of the pyridine molecule the cobalt ion induces spin transitions. The predicted magnetic properties of the studied systems suggest that they can be used as prototypes for the design of molecular electronic devices.

The topology of the electron density and the nature of donor-acceptor interactions in copper-based glycinehydroximate metallamacrocycles bearing calcium(ii) and yttrium(iii) have been studied for the first time in terms of the density functional theory (DFT). The DFT calculations at the M06/Def2-TZVP level were performed taking into account non-specific (PCM) and specific solvation. Quantitative estimations of the donor-acceptor interactions and topological properties of the electron density were obtained. According to them, the thermodynamic stability of the yttrium complex is higher than that of the calcium analog. The calculated values of the Gibbs energy changes indicate the spontaneous substitution of Ca²⁺ by Y³⁺ in the metallamacrocycle in an aqueous medium.

Cobalt(iii) complexes with different 4,6-di-tert-butyl-N-(aryl)-o-iminobenzosemiquinone ligands were synthesized. Four-, five-, or six-coordinate cobalt(iii) derivatives can be prepared using various starting metal compounds (CoCl₂•6H₂O, (acac)₂Co•2H₂O) and varying substituents in the N-aryl moiety of the organic ligand. The structures of five synthesized compounds were determined by X-ray diffraction. The electronic and spin states of the five-coordinate cobalt(iii) complexes were studied in detail by DFT quantum chemical calculations.

A new method is proposed for the one-step synthesis of tetrahedral rhenium chalcocyanide cluster complexes [{Re₄(µ₃-Q)₄}(CN)₁₂]⁴⁻ (Q = S, Se, Te) using rhenium(iii) iodide as the starting compound. A cluster complex of the composition K4[{Re₄S₄}(CN)₁₂]•H₂O was synthesized for the first time and characterized by X-ray diffraction.

Two new metal-organic frameworks based on magnesium(ii) ions, [Mg₄(bdc)₃(dma)₆(NO₃)₂]•DMA (1; bdc is 1,4-benzenedicarboxylate; dma, DMA is N,N-dimethylacetamide) and [Mg₃(bpdc)₃(nmp)₄] (2; bpdc is 4,4´-biphenyldicarboxylate; nmp is N-methylpyrrolidone), were synthesized in DMA or NMP, respectively. According to the single-crystal X-ray diffraction data, compound 1 is built of binuclear carboxylate units {Mg₂(O₂CR)₃}, which were previously not observed in metal-organic frameworks. Compound 2 is based on trinuclear carb oxylate units {Mg₃(O₂CR)₆}. Compound 1 has a layered structure (hcb topology), whereas compound 2 has a distorted three-dimensional cubic structure (pcu topology). The phase purity and chemical identity of the compounds were confirmed by IR spectroscopy, thermogravimetry, elemental analysis, and powder X-ray diffraction. Photoluminescence properties of both compounds are indicative of intraligand charge-transfer transitions of one (for 1) or two (for 2) types. Textural characteristics of an activated sample of 1 were measured by nitrogen and hydrogen adsorption at 77 K and by carbon dioxide adsorption at 195 K.

The kinetics of sulfonylation of several α-amino acids: Gly, dl-α-Ala, dl-Val, dl-Leu, l-Ile, dl-Thr, dl-Met, dl-Ser, and l-Pro and dipeptides: Gly—Gly, l-α-Ala—l-α-Ala, l-α-Ala—β-Ala, β-Ala—β-Ala in water—propan-2-ol and water—1,4-dioxane binary systems were studied by spectrophotometry. The rate constants for reactions involving α-amino acids and dipeptides vary in a range for 81–52900 L mol^–1 s^–1 and 1.49–75 L mol^–1 s^–1, respectively. A considerable decrease in the rate constants for sulfonylation of dipeptides compared to those of corresponding α-amino acids suggests that the basicity of amino compounds has a signifi cant eff ect on their reactivity. The activation parameters of the reactions of amino acids and dipeptides with 3-nitrobenzenesulfonyl chloride in aqueous organic media were calculated. The mechanism of sulfonylation of α-amino acids and the Gly—Gly dipeptide was simulated by constructing the potential energy surfaces of the gas-phase reactions and taking into account the specifi c solvation of nucleophiles. The processes under study were shown to proceed by the S_N2 mechanism, and the reaction pathway that corresponds to the nucleophilic attack along the near-axial direction is more favorable. It was found that the reactions of sulfonyl chlorides with solvated α-amino acids involve partial desolvation of α-amino acids occuring prior to the formation of activated complex.

The influence of molecular structural factors of covalently bound porphyrin-fullerene dyads and porphyrin—fullerene binary mixtures on photocurrent in model photoelectrochemical cells was studied. It was found that the photocurrent increased either by introducing solubilizing alkyl groups into the donor (porphyrin) or acceptor (fullerene) fragments, or by covalent binding porphyrin and fullerene into a donor-acceptor dyad.

A novel one-pot method based on the sequence of the Fisher reaction between nitroacetophenone and phenylhydrazines, the reduction with metallic tin directly in polyphosphoric acid, and acylation has been developed for the synthesis of indoloquinolines. The obtained indolo-[3,2-c]quinolines are precursors of the analogs of isocryptolepine alkaloid.

A series of optically active macrobicyclic cryptands were obtained by the Pd⁰-catalyzed amination reaction between (S)-2,2′-diamino-1,1′-binaphtalene (BINAM) and N,N′-bis-(bromobenzyl) derivatives of diaza-crown ethers. The dependence of yields of the macrobicyclic products on the structure of the diaza-crown ether derivatives was demonstrated. A comprehensive study of the effects of a number of optically active amino alcohols on the fluorescence spectra of the prepared compounds was carried out.

Cationic β-cyclodextrin derivatives containing residues of pharmacologically important acids linked by spacers of different lengths were obtained by treatment of mono-6-iodo-6-deoxy- and mono-6-tosyl-β-cyclodextrin with nucleophilic agents with terminal mono- and dimethylamino groups.

Thermodynamic functions (ΔG_f and ΔH_f) of clorinated dibenzo-p-dioxins (Cl_nDD) with n = 0–8 were calculated at the DFT level of theory using the B3LYP functional and extended 6–31** basis sets and used to analyze possible relationship of the structures and energy characteristics of these compounds with their toxicity. A new sequence of successive isodesmic reactions, which makes it possible to calculate chemical potentials μ_G and μ_H from the ΔG_f and ΔH_f values, has been proposed. In the framework of this approach, satisfactory linear correlations between the chemical potentials μ and the logarithms of toxicity of the corresponding polychlorodioxins were obtained for the first time.

The main principles of activity of the Russian Science Foundation (RSF) as a key tool for the support of fundamental and exploratory research in the Russian Federation are described. The opportunities provided by the RSF for project implementation at diferent levels, in particular, for the Presidential Research Project Program, are presented. The expert evaluation of proposed projects is considered in detail. Data on grant support for the Chemistry and Materials Science research field, which accounts for 13.6% of the whole amount of RSF financing, are given. Characteristic features of expert evaluation and performance indicators are outlined.