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Oxidation of nickel salen complexes results in highly reactive species, undergoing polymerisation within microseconds. As a result, oxidation chemistry of NiSalens is available only for sterically hindered complexes. In the present work, an unexpectedly high stability of a nickel complex with a thiophene-based salen ligand was reported and studied. Based on the electrochemical and spectroscopic studies supported by quantum chemical calculations, a rationale for the stability of oxidized nickel complexes with thiophene-based salen ligands was proposed. The introduction of the thiophene core leads to a depletion of spin density on peripheral carbon atoms of the oxidized complex, which switches off its intermolecular reactivity. Instead of this, the initial ligand-centered radical cation undergoes an intramolecular process, namely intervalence tautomerisation, which leads to a highly stable metal-centered oxidized state.

The article is devoted to the problem of revalorization (actualization of value) of the industrial heritage. Based on the analysis of the latest foreign and Russian publications, the author shows a wide range of options for repurposing industrial heritage objects, implemented in different countries for more than half a century. The attention is focused at some of the features of national approaches to the preservation and new use of old industrial buildings and territories. The author emphasizes the implemented and proposed projects for the adaptive reuse of factory buildings and sites in the Sverdlovsk region. Systematization of the studied material resulted in a classification of potential new functions for abandoned industrial facilities. The relevance of the study is due to the fact that typologization contributes both to a holistic understanding of the implemented solutions, specific achievements and miscalculations in the process of transforming territories, buildings, structures that lost their production function into modern objects which combine the memory of the previous stage of history and new useful functionality. The paper draws attention to the effectiveness of combining the efforts of professionals and civic initiative, cultural and government institutions, local, regional and state structures for the preservation of the national heritage of the industrial era. It emphasizes the integration of this underestimated resource into modern planning solutions for large and small cities, the creative social function of collective interaction in the process of revalorization industrial heritage.

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.

В статье рассматривается влияние современных технологий на сферу туризма и сервиса, а также негативная и позитивная оценка отечественных и иностранных специалистов к новым тенденциям. Рассматривается, как использование новшеств и ускорения обработки информации увеличивает объем услуг, оказываемых на туристском рынке. А разработка и внедрение новых интернет-технологий приводит к увеличению онлайн-бронирования туристических услуг.

Organic radical batteries (ORBs) are a promising class of electrochemical power sources employing organic radicals as redox-active groups. This article reports on the development of a versatile on-substrate electrode setup for spectroelectrochemical Electron Paramagnetic Resonance (EPR) measurements on redox conductive polymers for ORBs. Quantitative in-operando EPR experiments performed on electrochemical cells with a di-TEMPO Ni-Salen polymer as active electrode material demonstrate a strong decrease in the number of paramagnetic centers upon oxidizing the film. The distinct EPR signatures of the TEMPO-containing polymer and its fragments in different molecular environments are used to study its degradation upon repeated cycling. A comparison between the number of EPR-active sites and the number of electrochemically active charges, as measured by cyclic voltammetry, provides information on the nature of the degradation process. Low-temperature ex-situ pulse EPR measurements on the oxidized polymer film reveal the spectrum of dilute nitroxide species, which may be associated with electrochemically inactive islands. These experiments pave the way for advanced EPR techniques for accurately determining distances between adjacent paramagnetic centers and thus for identifying performance-limiting loss mechanisms, which can eventually help develop strategies for making ORBs powerful contenders on the path towards sustainable electrochemical power sources.

Electrochemical energy storage systems have a wide range of commercial applications. They keep energy and power even at temperatures up to +60 °C. However, the capacity and power of such energy storage systems reduce sharply at negative temperatures due to the difficulty of counterion injection into the electrode material. The application of organic electrode materials based on salen-type polymers is a prospective approach to the development of materials for low-temperature energy sources. Poly[Ni(CH3Salen)]–based electrode materials synthesized from different electrolytes were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and quartz crystal microgravimetry at temperatures from −40 °C to 20 °C. By analyzing data obtained in various electrolyte solutions, it was shown that at subzero temperatures, the process of injection into the polymer film, together with slow diffusion within the film, predominantly limit the electrochemical performance of electrode materials based on poly[Ni(CH3Salen)]. It was shown that the deposition of the polymer from solutions with larger cations allow the enhancement of the charge transfer due to the formation of porous structures facilitating the counter-ion diffusion.

В статье исследуются понятие экскурсионной деятельности, новые необычные экскурсии в современных условиях и новые, креативные экскурсионные услуги. Экскурсионная деятельность является одной из основных составляющих индустрии туризма. Именно экскурсовод помогает увидеть экскурсантам все важные и интересные объекты через призму исторических факторов, своих личных взглядов и сложенных легенд.

A mixed catalyst based on platinum and nickel oxide was obtained as a result of the synthesis and subsequent alkaline hydrolysis of thin polymer films of poly[Ni(Salen)] with platinum nanoparticles previously electrodeposited in its pores. The efficiency of catalyst operation was tested in oxygen electroreduction in an alkaline medium. A distinction of the catalyst is its high activity and tolerance to methanol impurities compared with commercial analogs.

Conductive polymers are widely used as active and auxiliary materials for organic photovoltaic cells due to their easily tunable properties, high electronic conductivity, and light absorption. Several conductive polymers show the cathodic photogalvanic effect in pristine state. Recently, photoelectrochemical oxygen reduction has been demonstrated for nickel complexes of Salen-type ligands. Herein, we report an unexpected inversion of the photogalvanic effect caused by doping of the NiSalen polymers with anionic porphyrins. The observed effect was studied by means of UV-Vis spectroscopy, cyclic voltammetry and chopped light chronoamperometry. While pristine NiSalens exhibit cathodic photopolarization, doping with porphyrins inverts the polarization. As a result, photoelectrochemical oxidation of the ascorbate proceeds smoothly on the NiSalen electrode doped with zinc porphyrins. The highest photocurrents were observed on NiSalen polymer with o-phenylene imine bridge, doped with anionic zinc porphyrin. Assuming this, porphyrin serves both as a catalytic center for the oxidation of ascorbate and an internal electron donor, facilitating the photoinduced charge transport and anodic depolarization.

Materials with a positive temperature coefficient have many applications, including overcharge and over-temperature protection in lithium-ion (Li-ion) batteries. The thermoresistive properties of an electrically conductive polymer, based on a Ni(salen)-type backbone, known as polyNiMeOSalen, were evaluated by means of in situ resistivity measurements. It was found that the polymer was conductive at temperatures below 220 &deg, C, however, the polymer increased in resistivity by three orders of magnitude upon reaching 250 &deg, C. Thermogravimetric results combined with elemental analyses revealed that the switch from the insulation stage to the conductive stage resulted from thermally dedoping the polymer. Electrochemical studies demonstrated that a polymer retains its electroactivity when it is heated and can be recovered to a conductive state through oxidation via electrochemical doping in an electrolyte solution.

The review focuses on variable-conductivity materials used to protect lithium-ion batteries from ignition. Examples of emergency situations arising in the operation of such batteries are given and their causes are considered. Thermal runaway that results in ignition of a lithium-ion battery and the chemical reactions accompanying this process are discussed. Internal battery protection using variable-resistance temperature- or voltage-sensitive components is described. Various approaches to the prevention of thermal runaway by modifying a battery with thermo- and voltage-resistive materials are summarized and analyzed. The advantages and drawbacks of various types of materials of this kind are demonstrated. Particular attention is paid to the practical significance of the creation and application of protective variable-resistance materials and approaches to the design of this kind of materials. The bibliography includes 165 references.

The influence of the structure of diimine bridge in the Schiff’s bases (derivatives of N,N'-ethylenebissalicylimine) on the rate of the loss of electroactivity of their complexes with nickel in acetonitrile containing 0.1 M of tetraethylammonium tetrafluoroborate (anhydrous and upon addition of 1 wt % of water) has been studied. It has been shown that the presence of bulky yet light methyl groups in the structure of diimine bridge significantly reduced the loss of electroactivity (37% of the initial capacity retained after 50 cycles) as compared to the ligand containing no substituents and containing phenyl group as the substituent (17 and 20%, respectively, of initial capacity retained after 50 cycles).

A novel electrode material was prepared by electrochemical oxidation of [4,4′-phenylazo-2,2′-(ethylenediimino-κ2N-methyl)diphenolate-κ2O]nickel, a [Ni(II)(salen)]-type complex, in chlorinated solvent. The chemical structure of the material was explored by FTIR, NMR and XPS techniques to determine the main components of the material and the nature of the linkage between them. The morphology of the material films was explored by SEM analysis. The electrochemical properties of the new material were studied by a set of voltammetric methods and an unusual stability of the material in aqueous medium was observed.

Polymeric transition metal complexes with salen-type Schiff base ligands are considered as promising materials for modification of electrical double layer capacitor electrodes. Electrochemical properties of these polymers that define their performance in supercapacitors should be influenced by the ligand structure but this influence has never been systematically investigated. This article describes results of a comparative study of capacitance and charge transfer rate in polymeric nickel complexes with six different salen-type ligands using electrochemical impedance spectroscopy, analyzes advantages and limitations of this method vs. cyclic voltammetry, and provides some insights into the structure and morphology of nickel-salen type polymers. Analysis of results obtained by different analytical techniques shows that introduction of methoxy-substituents into the phenyl rings of the salen ligand and different substituents to the diamine bridge of the ligand causes noticeable changes in electrochemical properties of corresponding polymeric nickel complexes. Experimentally obtained values of gravimetric and volumetric capacitance, as well as effective charge diffusion coefficient provide guidelines for selection of most suitable nickel-salen type polymers for application in energy storage devices, including supercapacitors.

Overcharge of Li-ion cells is one of the causes of severe safety problems. Despite many efforts to prevent development of adverse processes at overcharge conditions by using Battery Management Systems, chemical protection remains the most fail-safe solution. In the present work we describe novel approach to overcharge protection of Li-ion cells, which is provided by use of electrically conductive polymer that change electrical conductivity from conductive to insulating stage. The layer of such polymer, deposited between the LiFePO4 -based cathode material and current collector, increase the electrode resistance in more than 20 times when the cell voltage exceeds 4.2 V, acting as a chemical circuit breaker. At 5 V overcharge it allows reversible charge-discharge of the cell without developing of adverse process, while at 6 V overcharge it terminates the cell operation before electrolyte decomposition starts, reducing amount of evolved gases in 4 times compared to non-protected cell.

A novel approach to regulate nanoparticles morphology using capping agents (etidronic, succinic, tartaric and salicylic acids) in hydrothermal synthesis is presented. UV–Vis and FTIR spectra showed that influence of the capping agents is based on the interaction with particles surface during the solid phase formation. For na-VO2 nanorods a 1st order phase transition at 275 K was demonstrated using vibration sample magnetometry. Differential scanning calorimetry showed that this transition is accompanied by 2nd order transition at 320 K. Decrease in rods thickness and length for sal-VO2 and suc-VO2 made the transition less expressed and its temperature lowered from 275 to 150 K. Addition of tartaric and etidronic acids led to change of particles shape from rods to spheres and eliminated all the transitional changes in magnetic properties. Charge-discharge tests revealed that initial discharge capacity of nanorods was 100 mA h g−1, which is three times higher than that of spheres.

The results of the synthesis and investigation of new composite functional materials are presented. The new materials are conductive polymer layers of the cobalt, nickel, and palladium complexes with the Schiff bases (poly[MSchiff)]) with gold and platinum nanoelectrodes inserted into the layers using the electrochemical deposition method. The materials were studied by cyclic voltammetry, impedance spectroscopy, scanning electron microscopy with X-ray microanalysis, and a quartz crystal microbalance. The composite materials poly[Ni(Schiff)]/Pt and poly[Co(Schiff)]/Au exhibit catalytic activity in the reactions of hydrogen evolution and electroreduction of molecular oxygen, respectively.

Effect of addition of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) conducting polymer on the structure and properties of a cathode material based on lithium iron phosphate was studied. The X-ray diffraction method was used to examine the structure of lithium iron phosphate in a freshly prepared C-LiFePO4/C/PEDOTS:PSS composite material and in that subjected to a prolonged cycling. The chargedischarge characteristics of the cathode material of the conventional composition, which contains carbon black and poly(vinylidene fluoride) binder, and a new composition with addition of PEDOT:PSS were compared. The specific capacity of C-LiFePO4/C/PEDOT:PSS was 165 mA h g−1 (at 0.2C current), which substantially exceeds the specific capacity of the LiFePO4 material in the conventional composition.

Polymer complexes of nickel with SalEn-type ligands (SalEn = N,N′-bis (salicylidene) ethylenediamine) possess a number of unique properties, such as high redox conductivity, electrochromic behavior and selective catalytic activity in heterogeneous reactions. However, the mechanism of their redox transformation is still not clear. To understand this mechanism, we have performed a combined study of electrochemical and spectral properties of polymers derived from nickel complexes with various SalEn-type ligands containing methoxy substituents in phenyl rings, and methyl substituents in imino bridges. Experimental data were correlated with the results of density functional theory (DFT) calculations for model chains consisting of one to four monomer units. We found that, in acetonitrile-based supporting electrolyte, oxidation of such complexes, regardless of ligand substituents, proceeds via two routes, leading to formation of two oxidized forms: for the first one, a good correlation between experimental and computation results was observed. It has been demonstrated that positive charge in this form is delocalized in the phenyl moieties of ligand. The second oxidized form is stable only in coordinating solvents at high electrode polarizations and is likely to have the charge localized on the central metal atom, stabilized by axial coordination of solvent molecules. The complicated electrochemical response of each of the polymers that we have studied can be explained in the scope of this model without any additional assumptions by taking into account conversion of one oxidized form into another. Understanding the solvent effect on the oxidation route of the complexes will enable controlling their catalytic properties and stability.

On the basis of archival sources, pre-revolutionary periodicals, folklore materials, memories, modern historiography and taking into account the relevant queries of the Russian society the authors analyze the impact of the First World War on the peripheral region of Russia – the Urals. The study is based on anthropologically oriented approach, which allows understanding various aspects of the social life in the rear during the war. Industrial contribution of the Urals to the defense of the country is well-known. The article is devoted to less explored issues: assessment of public sentiment and the level of self-organization, the features of social life in wartime, the role of the Russian Orthodox Church and the clergy in public life in the Ural cities, the role of public institutions and behavior of socio-professional groups. The authors conclude that, despite the Urals’ remoteness from the battlefield, the First World War had a profound impact on the life of the region, which made a significant human, economic, and art contribution to the battle against the enemy.

Electrochemical cells using LiFePO4 cathode material are considered one of the safest and most resistant to overcharging among Li-ion batteries. However, if LiFePO4-based electrodes are exposed to high potentials, surface and structural changes may occur in the electrode material. In this study Li/LiFePO4 half-cells were overcharged under different modes with variable cut-off voltages and charge currents. The change in voltage profile, discharge capacity, surface layers composition, and crystalline structure were characterized after overcharge cycles. It was demonstrated that the cathode material is resistant to short-term overcharging up to 5 V, but undergoes irreversible changes with increasing overcharge time or potential. Thus, despite the well-known tolerance of LiFePO4-based batteries to overcharge, a long overcharge time or high cut-off voltage leads to destructive changes in the cathode and should be avoided.

A new functional conducting poly-3,4-ethylenedioxythiopene:polystyrene sulfonate/carboxymethylcellulose binder for improvement of capacity of LiFePO 4 -based cathode materials was proposed. The carbon black free composite material consisting of 96 wt% of C-LiFePO 4 and 4 wt% of binder showed the discharge capacity 148 mAh g −1 (at 0.2 C, normalized by the electrode mass). The proposed cathode material exhibited excellent rate capability with discharge capacity 126 mAh g −1 at 5 C as well as good cycling stability at 1 C (less than 1% decay after 100 cycles).

Electrochemical properties of glassy carbon electrodes modified by two polymer films of different nickel complexes with Schiff base ligands containing methoxy substituents in their aromatic parts were studied in acetonitrile solutions with cyclic voltammetry, quartz crystal microbalance, atomic force microscopy, and impedance spectroscopy. It was observed that introduction of such substituents leads to a noticeable splitting of cycling voltammetric curves into at least two ox/red transitions. In addition, solvent flows accompanying the counter-ions ones during charging/discharge processes within the films appeared significantly greater than those observed in the case of non-substituted ligands. The obtained impedance results as a whole were satisfactorily treated in scope of the so-called model of homogeneous films with two kinds of charge carriers. However, determinations of the Warburg constant as a function of the electrode potential require additional verifications, at least in the ranges of overlapping ox/red transitions. In particular, it was established that in this region the impedance frequency dependence was some superposition of the diffusion (Warburg) and the pseudo-capacitive constituents. This, most likely, resulted from the presence of three kinds of charge carriers in the film interior.

Ethnic tourism is one of the trends of tourism with its own distinguished ethnical, language and cultural components. The purpose of this type of tourism is to get acquainted with the way of life, culture, traditions and customs of the people who live in harmony with the natural environment. The Republic Mari El is a region where many nationalities and ethnic groups live in friendship and consent. But the nation, entitled to this territory, remains the Mari, who, regardless of the assimilation process, managed to preserve their own language, traditional folk clothes, their customs and traditions, their philosophy and religion, folk songs and dance. When organizing an ethnic tour, the content of the tour and the form of the organization of the children’s activity should be clearly defined. This also involves defining the level of the students’ awareness of the aspects of history and culture, as well as biography and geography. The acquired results of the survey helped to specify the content of ethnic tours for children in the Republic Mari El. As a form of organization of ethnic tourism we suggest visit in our Republic’s cities and districts, organizing game program sand trainings, as well as meetings with the famous folk craftsmen, participating in folk feasts, etc. The final form of ethnic tourism activity is a research and practice conference, where the students present their own research projects.