Fine Chemical Technologies

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Vol 12, No 2 (2017)
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5-33 629
To understand the dynamic features of molecular systems with a complex landscape of potential energy surfaces, it is necessary to study them in the associated 4D space-time continuum. The introduction of time in the diffraction methods and the development of coherent principles of the research process opened up new approaches for the study of the dynamics of wave packets, intermediates and transient states of the chemical reactions, short-lived compounds in the gaseous and condensed media. Time-resolved electron diffraction, the new method for the structural dynamic studies of free molecules, clusters and condensed matter, differs from the traditional method of electron diffraction both in the experimental part and in the theoretical approaches used in the interpretation of diffraction data. Here there is particularly pronounced the need of a corresponding theoretical basis for the processing of the electron diffraction data and the results of spectral investigations of the coherent dynamics in the field of intense ultrashort laser radiation. Such unified and integrated approach can be formulated using the adiabatic potential energy surfaces of the ground and excited states of the systems under study. The combination of state-of-the-art optical techniques and electron diffraction methods based on different physical phenomena, but complementing each other, opens up new possibilities of the structural studies at time sequences of ultrashort duration. It provides the required integration of the triad, "structure - dynamics - functions" in chemistry, biology and materials science.
34-41 689
Complex compounds NiCl2·2HMTA·10H2O (1), CoCl2·2HMTA·10H2O (2), CoCl2·HMTA·4.5H2O (3) were prepared by the reaction of nickel(II) and cobalt(II) chlorides with urotropine (HMTA). Compounds 1 and 2 are isostructural, their structure corresponds to the earlier studied crystal structure [Ni(H2O)6]Cl2·4H2O·2HMTA. Thermal destruction of the complex compounds 1-3 was studied by TGA and high-temperature IR-spectroscopy. The TGA curve for compound 1 shows stepwise mass loss caused by two-stage loss of all water molecules (up to 170°C) and one urotropine molecule (up to 270°C) followed by decomposition of NiCl2·HMTA. The X-ray diffraction pattern of the resulting solid shows no reflections typical for the metal and its simplest nitrogen-, carbon- and chlorine-containing compounds. Thermal decomposition of сompounds 2 and 3 proceed similarly, but water is removed in one stage. IR spectra, which were recorded at high temperature (up to 220-230°C) show gradual decrease of intensity of the bands assigned to vibrations of water molecules. The bands of the methylene groups of urotropine do not change on heating. However, the bands of the C-N vibrations shift from ~1050 and ~1008 cm-1 in the spectra of urotropine and [M(H2O)6](HMTA)2Cl2·4H2O to 1015-1019 and 984-995 cm-1, respectively, indicating coordination of urotropine molecules instead of the removed water molecules. The long-wave IR spectra for NiCl2·6H2O and compound 1 at ambient temperature show bands of Ni-O stretching vibrations and O-Ni-O bending vibrations. After heating 1 at 115° C, bands of Ni-N and Ni-Cl appear, which indicates the coordination of urotropine molecules and chloride ions after the removal of outer-sphere and inner-sphere water molecules.


42-49 375
Perspective ways of power saving in the distillation of liquid mixtures are considered. The phenomenon of internal energy saving on theoretical plates is considered in detail. As shown in this article, the phenomenon depends on the number of theoretical plates in the rectifying and stripping sections of the column and also on the aggregative state of the feed mixture. The processes of heat and mass transfer on real plates with various values of efficiency factor are considered. Blocks of real plates equivalent to one theoretical stage, that is, blocks where the leaving flows of the liquid and vapor are in equilibrium, are isolated. Analogically, heat and mass transfer in apparatuses with a continuous phase contact having a layer height providing one theoretical plate is considered. It is proved that internal energy saving in filled rectifying columns with real plates also depends on the number of theoretical plates and the aggregative state of the initial mixture.
50-61 573
Heterogeneous oxidative chlorination of methane was investigated. The target product is methyl chloride. The investigated terms and conditions of oxychlorination of methane: process temperature 400°C, pressure 0.1-0.9 MPa, catalyst (% weight.): copper chloride (II) 1-8%; potassium chloride 2.5%; lanthanum chloride 1%; carrier - aluminosilicate. Powder X-ray diffractometry and electron microscopy showed that the active catalyst components (CuCl2, KCl, LaCl3) are unevenly distributed on the support surface (α-Al2O3·SiO2) and form agglomerates with a high salt content, including binary chlorides such as KCuCl3, K2CuCl3 or K2CuCl4, hydrates K2CuCl4·2H2O and CuCl2·2H2O and hydroxychlorides Cu3Cl4(OH)2 and Cu2Cl(OH)3. The kinetics of methane oxychlorination was studied in a gradientless reactor at 400°C and pressure 0.1 - 0.9 MPa by varying the partial pressures of the reactants. Analysis of the products was carried out by GC. An equation of the reaction rate including partial pressures of methane, hydrogen chloride and water to the 0.77, 0.01 and 0.64 power, respectively, but of zero order by oxygen and chlorine provides an adequate description of methyl chloride formation rate. Significant influence of water partial pressure is proved for the reaction under consideration.


62-71 357
The synthesis of a dimer consisting of γ-thymine chiral monomer based on L-Ala and thymine aeg-PNA monomer (synthesized from deuterated glycine), in which the methylene protons of the pseudopeptide residue were exchanged with deuterium atoms, was described. The deuterated monomer was introduced into acylation reaction by means of a mixed anhydride procedure with γ-PNA chiral monomer trifluoroacetate based on L-Ala. The latter was obtained from the fully protected thymine monomer by the reaction with trifluoroacetic acid. The structure and purity of the target monomer were confirmed by NMR-spectroscopy, and the elemental composition was estimated by quantitative elemental analysis. The double quantum filtered COSY-NMR-spectroscopy (DQF-COSY) method was used to determine the methylene signals of the dimer chiral fragment. With the use of the spectrum analysis, the chemical shifts and calculated spin-spin coupling constants of the protons from the dimer chiral part were found. Given that Karplus equation associates the value of the dihedral angle between the vicinal protons with their spin-spin coupling constant, it was concluded that the chiral fragment is in the right-helix conformation for all the dimer rotamers.
72-80 458
Malignant tumors are the second most frequent cause of death after cardiovascular diseases. The photodynamic therapy based on the interaction of laser light with different photosensitizers was discovered in the 20th century as one of treatment methods. When using photosensitizers, the process of singlet oxygen and other active forms generation is observed in both malignant and healthy body tissues, which leads to a number of adverse reactions. More promising diagnostic compounds that do not have these disadvantages are ytterbium porphyrin complexes. These compounds slightly generate singlet oxygen under light irradiation, while maintaining a high level of tumorotropic agents as for therapeutic photosensitizers. This work continues a series of studies devoted to the analysis of physicochemical properties of Yb-complex 2,4-dimetoxyhematoporphyrin IX as a promising marker for fluorescent diagnostics of various tumors. Pharmaceutical compositions based on Yb3+-dimetoxyhematoporphyrin IX dipotassium salt were created. These compositions are capable of accumulating in the sites of inflammation and proliferation in diseases of mucosal membranes and cancer lesions. Toxicological and pharmacokinetic studies were carried out with the use of laboratory animals and volunteers. The analysis results showed that the pharmaceutical compositions are perspective for use in clinical practice.
81-99 376
In the present study, a rapid, sensitive, and selective method for determination of several synthetic analogues of gonadotropin-releasing hormone in human urine by solid-phase extraction and ultraperformance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was developed. Various parameters affecting sample preparation, LC separation, and MS/MS detection were investigated, and optimized conditions were identified. The UPLC-MS/MS system was equipped with an electrospray ion source operating in positive ion mode with selected reaction monitoring. Leuprolide-13С6 was used as internal standard for analytes quantitative assessment. The proposed method was validated considering the parameters specificity, linearity (0.1-10 ng/ml), recovery (52-98%), limit of detection (0.1 ng/ml), matrix effects and stability.


100-104 372
The rheological properties of polysulfide (PPS) melts and composite materials based on them were investigated in a wide range of temperatures and concentrations of fillers of different nature. It was established that the introduction of rheological additives into dispersed and hybrid-filled composite materials allows significantly reducing the viscosity and improving the processability of the compositions. Introduction of heat-stabilizing additives into PPS allows expanding the temperature interval of processing the composite materials based on PFC from 320 to 340°С. Complete thermal stability curves for the PPS compositions in a wide temperature range were obtained.
105-110 515
The article is devoted to the 100th anniversary of the birth of Nikolay Prokofyevich Fedorenko, a graduate of M.V. Lomonosov MITHT, a participant of the Great Patriotic War, the head of MITHT department for chemical industry economy (1951-1962), since 1953 to 1958 - the deputy director of MITHT for studies. N.P. Fedorenko is Doctor of Economics, professor, academician of the Academy of Sciences of the USSR, member of the presidium of the Academy of Sciences of the USSR, academician-secretary of the Economy department of the Academy of Sciences of the USSR, one of the main founders and the first director of the Central Economics and Mathematics Institute of the Academy of Sciences of the USSR (1963-1985). N.P. Fedorenko was the most talented organizer of the economic science. He made a large contribution to the chemicalization of the national economy, to the application of modern mathematical methods and computing hardware for economic research, to the planning, management and studying of the theoretical and methodological bases of optimum performance of economy.

ISSN 2410-6593 (Print)
ISSN 2686-7575 (Online)