Volume 92, Issue 8

A mini-review describes the development of the catalysis by Cu(I) complexes aimed at the formation of C–N bond at the Lomonosov MSU during 2010s. The main approach employs the amination of aryl and heteroaryl halides with the amines and polyamines, in this direction a great versatility of starting compounds was achieved: adamantane-containing amines, linear diamines, oxadiamines and polyamines, various aryl iodides and bromides, derivatives of pyridine, and quinoline were used for this purpose. In more peculiar cases, the copper catalysis was used for steroids transformations, including vinylation of azoles, wide-spread “click” reactions for the conjugate syntheses, and successful heterogenezation of the copper catalysts were also undertaken.

Cancer is one of the most common causes of death in modern medicine. Molecular design of novel substances with pharmacological activity is one of the goals of medicinal inorganic chemistry. Platinum complexes are widely used in the treatment of cancer, despite high efficacy their use is limited by side effects, as well as primary or acquired resistance. In this regard, the search for novel metal-containing antitumor compounds is underway. Organotins and gold compounds are promising pharmacological agents with anti-cancer properties. The introduction of protective antioxidant fragments into inorganic compounds molecules is a way to reduce the side effects of anti-cancer drugs on healthy cells. 2,6-dialkylphenols belonging to vitamin E (α-tocopherol) mimetics are widely used as antioxidants and stabilizers. The properties of Ph 3 SnCl ( Sn-I ), Ph 3 PAuCl ( Au-I ) and complexes Ph 3 SnSR ( Sn-II ) and Ph 3 PAuSR ( Au-II ) based on 2,6-di- tert -butyl-4-mercaptophenol ( RSH ) as radical scavengers and reducing agents were studied in model reactions. For Sn-II and Au-II the comparative study of cytotoxic action was made and the IC 50 values on different cancer cell lines were found to be depended on the nature of metal. In general, Sn(IV) complexes possessed higher cytotoxicity than Au(I) complexes. In order to clarify the mechanism of cytotoxic mode of action the effect of compounds on Fe 3+ -induced lipid peroxidation, mitochondrial potential and mitochondrial permeability, cell cycle and induction of apoptosis was studied. Organotin compounds can bind tubulin SH-groups and inhibit its polymerization by a dose-dependent mechanism, whereas gold compounds inhibit Thioredoxin reductase ( TrxR ). In vivo experiments on acute toxicity of Sn-II and Au-II proved their moderate toxic action that opens prospects for the further study as antitumor agents.

Colchicine derivative bearing substituted bispidine moiety, namely N-{7-(3,7-Di-(tert-butoxycarbonyl)-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonan-9-yl)-oxy-7-oxoheptanoyl}-N-deacetylcolchicine, was synthesized and tested for its effect on the net of microtubules (MT) in lung cancer cells A549. The compound induced not only MT depolymerization but stimulated the formation of small tubulin aggregates and long tubulin fibrils localized mainly around nuclei. The assemblies were morphologically different from tubulin clusters induced by structurally related anticancer agent tubuloclustin. The biotests data demonstrate that the depolymerization takes place for both pure tubulin and tubulin in cellulo, while fibrils are formed only in the cells. The research data of structure–activity relationship for several similar colchicine derivatives synthesized in the work give evidence for the proposition that the initial conjugate may interact not only with tubulin and MT in the cells, but also with MT-associated proteins, involved in the process of tubulin polymerization. The ability to affect simultaneously MAP – tubulin interactions opens attractive prospects in the design of novel anticancer agents.

The article describes a comprehensive mass spectrometric approach to the study of surfaces of structural materials. The combined use of thermal desorption mass spectrometry, gas and liquid chromatography, and laser desorption/ionization mass spectrometry (LDI) to provide information about the surface and surface layers of materials is proposed. The suggested method allows one to determine the thermodynamic characteristics of compounds and surface contaminants adsorbed on surfaces, as well as surface layers, to determine the composition of volatile and non-volatile contaminants on the surface, and to determine the nature of the distribution over the surface of these compounds. The method allows to obtain the most complete information about the surface condition and can be used to predict the life of structural materials.

Metal- salen polymers are electrochemically active metallopolymers functionalized with multiple redox centers, with a potential for high performance in various fields such as heterogeneous catalysis, chemical sensors, energy conversion, saving, and storage. In light of the growing world demand for the development of superior energy storage systems, the prospects of employing these polymers for advancing the performance of supercapacitors and lithium-ion batteries are particularly interesting. This article provides a general overview of the results of investigating key structure-property relationships of metal- salen polymers and using them to design polymer-modified electrodes with improved energy storage characteristics. The results of independent and collaborative studies conducted by the members of two research groups currently affiliated to the Saint–Petersburg State University and the Ioffe Institute, respectively, along with the related data from other studies are presented in this review.

Modern high-temperature technologies and methods of production of advanced materials impose new requirements on the quality of information on physicochemical properties of oxide systems at high temperatures. Normally, thermodynamic approach for these purposes is the most fundamental and essential. Great attention was paid by M.M. Shultz to extensive development of this approach in the studies of oxide melts, crystals, glasses, ceramics, and coatings using calorimetric, EMF, and high temperature mass spectrometric methods. Advantages of the thermodynamic approach were illustrated by examples of application of the Knudsen effusion mass spectrometric method to studies of oxide systems and materials, which were crucial for the further development of space and aviation industry, energetics, instrument making, communication engineering, metallurgy, energy-saving, and environmental safety. In the discussion of the regularities of vaporization processes and changes of thermodynamic properties in oxide systems, a number of particular systems based on silica and hafnia was considered in detail. Modeling was carried out for these systems using the Generalized Lattice Theory of Associated Solutions. The obtained results assert a necessity for creation of the national thermodynamic data- and model bases essential for further prediction of phase equilibria in oxide systems and materials at high temperatures.

The competitive routes were found for three-component cyclization of polyfluoroalkyl-3-oxo esters, methyl ketones with 3-amino alcohols. It was shown that the reactions with 3-aminopropanol in 1,4-dioxane predominantly lead to hexahydropyrido[2,1- b ][1,3]oxazin-6-ones, and in ethanol to 3-hydroxypropylaminocyclohexenones. In contrast, cyclizations with 2-aminoethanol and its analogues, regardless of the reaction conditions, yield hexahydrooxazolo[3,2- a ]pyridin-5-ones as the main products. The trans - and cis- diastereomeric structure of heterocycles was established using X-ray and 1 H, 19 F, 13 C NMR spectroscopy, 2D 1 H- 13 C HSQC and HMBC experiments. The mechanism is proposed for competitive transformations of polyfluoroalkyl-3-oxo esters, methyl ketones with 3-amino alcohols.

Using purine as a scaffold, the methods for preparation of novel 2-aminopurine and purine derivatives substituted at position C 6 by the fragments of natural amino acids, short peptides, and N -heterocycles, including enantiopure ones, have been proposed. The methods for determination of the enantiomeric purity of the obtained chiral compounds have been developed. Conjugates exhibiting high antimycobacterial or anti-herpesvirus activity against both laboratory and multidrug-resistant strains were revealed among the obtained compounds.

By the methods of MALDI and mass spectroscopy with the detection of positively and negatively charged ions, it was found that the reaction of elemental sulfur and 1,3-dimethylimidazolium dimethylphosphate is accompanied by the opening of the S 8 ring. 1 H, 13 C, 15 N and 31 P NMR spectroscopy showed that the interaction of S 8 and 1,3-dimethylimidazolium dimethylphosphate proceeds exclusively on the oxygen atom of the dimethylphosphate anion carrying a negative charge. Kohn-Sham calculations at B3LYP/STO-3G, B3LYP/6-31G* and B3LYP/6-311G* levels of theory confirmed that the reaction of S 8 with dimethylphosphate anion is possible.

Nowadays, hydrogen has become not only an extremely important chemical product but also a promising clean energy carrier for replacing fossil fuels. Production of molecular H 2 through electrochemical hydrogen evolution reactions is crucial for the development of clean-energy technologies. The development of economically viable and efficient H 2 production/oxidation catalysts is a key step in the creation of H 2 -based renewable energy infrastructure. Intrinsic limitations of both natural enzymes and synthetic materials have led researchers to explore enzyme-induced catalysts to realize a high current density at a low overpotential. In recent times, highly active widespread numerous electrocatalysts, both homogeneous or heterogeneous (immobilized on the electrode), such as transition metal complexes, heteroatom- or metal-doped nanocarbons, metal-organic frameworks, and other metal derivatives (calix [4] resorcinols, pectates, etc.), which are, to one extent or another, structural or functional analogs of hydrogenases, have been extensively studied as alternatives for Pt-based catalysts, demonstrating prospects for the development of a “hydrogen economy”. This mini-review generalizes some achievements in the field of development of new electrocatalysts for H 2 production/oxidation and their application for fuel cells, mainly focuses on the consideration of the catalytic activity of M[P 2 N 2 ] 2 2+ (M = Ni, Fe) complexes and other nickel structures which have been recently obtained.

It is shown that self-heating of a compacted sample made of nonpassivated iron nanopowder is not uniform, although it begins simultaneously within the entire surface of the sample. It is found that the maximum temperature of self-heating decreases with an increase in relative density of samples, which indicates that the oxidation process is limited by the diffusion supply of oxidant. It is shown that the process of interaction of samples with the air occurs in a superficial mode. A qualitative agreement of the results of the theoretical analysis with experimental data is obtained. The possibility of passivation of compacted samples made of iron nanopowder is experimentally established.

The paper describes synthesis and testing of novel biodegradable polylactide-based polymer membranes with desired mechanical properties, which are capable of sustained and directed release of biomacromolecules with high molecular weight (in particular, streptokinase; m.w. 47 kDa). Streptokinase is a pharmaceutical agent, possessing a pronounced thrombolytic activity. The membranes synthesized had a percentage elongation of 2–11% and tensile strength of 25–85 MPa. They were biodegradable – yet being stored in aqueous media in the absence of biological objects, would be dissolved by no more than 10% in 6 months. The synthesized membranes were capable of controlled release of streptokinase into the intercellular space, with the enzyme retaining more than 90% of its initial activity. The rate of streptokinase release from the membranes varied from 0.01 to 0.04 mg/day per cm 2 of membrane surface. The membrane samples tested in the work did not have any short-term toxic effects on the cells growing de novo on the membrane surface. The mitotic index of those cells was approximately 1.5%, and the number of non-viable cells on the surface of the polymer films did not exceed 3–4% of their total amount. The implantation of the synthesized polymers – as both individual films and coatings of nitinol stents – was not accompanied by any postoperative complications. The subsequent histological examination revealed no abnormalities. Two months after the implantation of polymer films, only traces of polylactide were found in the implant-surrounding tissues. The implantation of stents coated with streptokinase-containing polymers resulted in the formation of a mature and thick connective-tissue capsules. Thus, the polylactide membranes synthesized and tested in this work are biodegradable, possess the necessary mechanical properties and are capable of sustained and directed release of streptokinase macromolecules.

The rapid development of additive technologies in recent years is accompanied by their intensive introduction into various fields of science and related technologies, including analytical chemistry. The use of 3D printing in analytical instrumentation, in particular, for making prototypes of new equipment and manufacturing parts having complex internal spatial configuration, has been proved as exceptionally effective. Additional opportunities for the widespread introduction of 3D printing technologies are associated with the development of new optically transparent, current- and thermo-conductive materials, various composite materials with desired properties, as well as possibilities for printing with the simultaneous combination of several materials in one product. This review will focus on the application of 3D printing for production of new advanced analytical devices, such as compact chromatographic columns for high performance liquid chromatography, flow reactors and flow cells for detectors, devices for passive concentration of toxic compounds and various integrated devices that allow significant improvements in chemical analysis. A special attention is paid to the complexity and functionality of 3D-printed devices.

The Mendeleev Periodic Table of Chemical Elements delivered a strong impetus to the development of fundamental and applied chemistry, chemical technology, analytical chemistry, and material sciences. Each element under the Periodic Table is an idealized substance with a certain structure and properties as defined by existing theoretical frameworks. In the real world, we deal with substances that are close in composition to the element of Periodic Table under study but differ in the presence of different elements in them – impurities that distort (sometimes radically) the structure and properties of the target research object. For many centuries, humanity has sought to obtain pure substances in order to achieve desired properties. In the second half of the 20 th century, a unique collection of high purity substances was created, which includes samples representing material artifacts, prototypes of elements of Periodic Table that contain record low contents of impurity elements. With ongoing scientific and technological progress, the achieved purity of substances continuously increases and, therefore, their approximation to idealized elements of Periodic Table. This is facilitated by: new technological processes for the production and storage of high purity substances with a constant decrease in the level of impurities; the creation of isotope-friendly substances; complexes of more highly sensitive multi-element analysis methods; identification of the unique properties of high purity substances, bringing them closer to the capabilities of analog elements of Periodic Table and much more. This article is devoted to progress in these areas. Special attention is also paid to the problems in modern analytical chemistry of high purity substances and the use of the latter in the metrology of chemical analysis as the standards of comparison.

A mini-review covers recent successes in the synthesis of ( S )-1,1′-binaphthyl-2,2′-diamine (BINAM) using Pd(0)-catalyzed amination reactions. As a result, versatile compounds with C 2-chiral backbone were synthesized, among them are derivatives bearing additional chiral amino and fluorophore groups like dansyl amide, 7-methoxycoumarin, 6-aminoquinoline, different macrocyclic compounds with oxadiamine and polyamine linkers were obtained as well. BINAM derivatives of various structures were evaluated as fluorescent enantioselective detectors for a series of model amino alcohols. Many of them were shown to be efficient in sensing certain enantiomers of the amino alcohols by selective changes in the emission in the presence of these analytes. Small changes in the structure of the BINAM derivatives lead to serious difference in the recognition ability of the compounds under investigation.