Transition-metal-mediated white phosphorus activation provides access to diverse polyphosphorus complexes, yet their catalytic potential remains unexplored. Herein, we report the first catalytic application of such a complex,[Co(Ph2PNHP(Ph2)PPPPP(Ph2)NHPPh2)]BF4, in the hydrogen evolution reaction (HER). Mechanistic studies unveil a novel metal-assisted ligand-centred pathway, where the supramolecular dimerization and the subsequent CoIII-CoII reduction initiate the H2 release accompanied by the amino/aminido transformation in PNP fragment of the ligand. The main intermediates of the catalytic process were determined by synthetic and computational methods and characterized by spectroscopy and XRD analyses. The complex demonstrates high turnover frequency of 10,280 s(-1) at an 0.6 V overpotential with 99 % faradaic efficiency, comparable to the most efficient ligand-centred catalytic systems reported to date. The obtained results offer new insights into the design of molecular catalysts for sustainable hydrogen production.

Main types of deposition of various functional coatings (gas-thermal, galvanic, paint-and-lacquer and diffusion ones) are considered. The requirements for materials forming the coatings, as well as the general requirements for the process of their deposition and the requirements directly for the resulting functional coatings themselves are given. Various technologies for ensuring described requirements have been analyzed.

The photocatalytic activity of 2D/2D/0D heterostructures based on few-layer black phosphorus (FLBP) g-C3N4/FLBP/Co2P in the reaction of photocatalytic hydrogen formation from an aqueous solution of triethanolamine under under visible light irradiation (400 nm) was studied for the first time. An original method for the preparation of the g‑C3N4/FLBP/Co2P composite photocatalyst is proposed, which consists of the solvothermal synthesis of cobalt phosphide Co2P nanoparticles, their immobilization on the surface of FLBP, and subsequent mixing of the FLBP/Co2P heterostructure with g‑C3N4. The synthesized photocatalysts were characterized by physicochemical analytical methods (X-ray diffraction, X-ray photoelectron spectroscopy, high-resolution transmission microscopy, energy-dispersive X-ray spectroscopy). The hydrogen evolution rate in the presence of the g‑C3N4/FLBP/Co2P heterostructure was 0.09 mmol g_cat^ - 1 h–1, which is 25 times higher than the same characteristic for the unmodified g‑C3N4 sample. The obtained numerical values of the photocatalytic activity are at the level of the literature values.

The electrochemical properties of [Co(Ph2PCH2P(Ph)2PPPPP(Ph)2CH2PPh2)]BF4 complex have been studied by the method of cyclic voltammetry. The electrochemical methylation of this complex have been cunducted in the presence of iodomethane which has led to the formation of phosphonium salt—ethylene bis(methyldiphenylphosphonium) diiodide as final product. It was found, that this reaction proceeds with the breakage of the P–P bonds in polyphosphorus ligand and with the formation of new P–C bonds.

The electrochemical properties of [Co(Ph2PCH2P(Ph)2PPPPP(Ph)2CH2PPh2)]BF4 complex have been studied by the method of cyclic voltammetry. The electrochemical methylation of this complex have been cunducted in the presence of iodomethane which has led to the formation of phosphonium salt—methylene bis(methyldiphenylphosphonium) diiodide as final product. It was found, that this reaction proceeds with the breakage of the P–P bonds in polyphosphorus ligand and with the formation of new P–C bonds.

Благодаря уникальным электронным и оптическим свойствам малослойный черный фосфор (МЧФ) является перспективным двумерным материалом для применения в различных областях химии и физики. Химическая функционализация поверхности МЧФ является эффективной стратегией для улучшения стабильности к окислению, а также для настройки и придания новых свойств фосфорному материалу. В данной работе предложен подход к иммобилизации комплекса [NiBr2(phen)] (где phen – 1,10-фенантролин) на поверхности МЧФ путем ковалентной функционализации МЧФ 1,10-фенантролином и последующим образованием комплекса с NiBr2. Полученные фосфорсодержащие материалы на основе МЧФ, функционализированного комплексом [NiBr2(phen)] охарактеризованы комплексом физико-химических методов, включая просвечивающую электронную микроскопию (ПЭМ), атомно-силовую микроскопию (АСМ), а также твердотельную ЯМР-, ЭДС-, КР- и ИК-спектроскопию.

A 2D material few-layer black phosphorus (FLBP) has promising applications in various fields of chemistry and physics due to its unique electronic and optical properties. Chemical functionalization of the FLBP surface is an effective strategy for improving the oxidative stability of the material, tuning its intrinsic properties or endowing it with new properties. The present work proposes an approach to the immobilization of the [NiBr2(phen)] complex (phen = 1, 10-phenanthroline) on the FLBP surface via covalent functionalization of FLBP with 1,10-phenanthroline and subsequent complexation with NiBr2. The obtained FLBP-based materials functionalized by the [NiBr2(phen)] complex were characterized by a set of physicochemical methods such as transmission electron microscopy, atomic force microscopy, solid-state NMR, energy-dispersive spectroscopy, Raman spectroscopy, and IR spectroscopy.

This paper presents an analytical analysis of the effect of heat losses on the possibility of occurrence of the most effective gas-phase combustion of a single boron particle in air at different initial temperatures and pressures of the oxidizing medium. The analysis is performed with account for the possibility that the particle enters into an air medium (its temperature is lower than the melting point of boron) after its ignition and the establishment of a steady gas-phase combustion. A method for calculating the maximum initial air temperature below which a burning boron particle cools down and extinguishes is developed. The boundaries of the regions of its gas-phase combustion and extinguishing are determined. It has been established that when a single boron particle in a state of gas-phase combustion enters air with a temperature below the melting point, the main factor determining the its combustion mechanism is the air temperature. Depending on the air temperature, either the gas-phase combustion of the particle continues or the particle cools down and the gas-phase combustion changes to heterogeneous combustion.

The main methods of surface preparation before applying functional coatings are considered. Promising ways of their modernization are identified. The influence of ultrasonic processing methods on the surface geometry is considered.

The controlled reaction between [Pt2(DVTMS)3], where DVTMS represents 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, and dialkylbiaryl phosphines (Buchwald ligands) 2-(di-tertb u t y l p h o s p h i n o ) b i p h e n y l (John P h o s, 1), 2(dicyclohexylphosphino)biphenyl (CyJohnPhos, 2), 2-di-tert-butylphosphino-2 ',4 ',6 '-triisopropylbiphenyl (tBuXPhos, 3), 2-dicyclohexylphosphino-2 ',4 ',6 '-triisopropylbiphenyl (XPhos, 4), 2dicyclohexylphosphino-2 ',6 '-dimethoxybiphenyl (SPhos, 5), 2dicyclohexylphosphino-2 '-(N,N-dimethylamino)biphenyl (DavePhos, 6), and 2-dicyclohexylphosphino-2 ',4 ',6 '-trimethoxybiphenyl (MeOSPhos, 7) generates an efficient platinum catalyst of type [Pt(DVTMS)(L)] (1a-7a), where L represents the Buchwald ligand, applied for hydrosilylation of phenylacetylene by diphenylsilane. The X-ray crystal structure analysis of the obtained Pt catalysts showed the presence of specific Pt-aryl interactions with the phenyl group of the dialkylbiarylphosphine ligand in complex 1a, while the same effect was not observed for the related 2 ',4 ',6 '-triisopropyl substituted aromatic ring in 3a. The evaluation of the steric parameters from X-ray diffraction analysis (XRD) showed the increase of the steric hindrances around the platinum atom improves the selectivity and the yield of the beta(E)-product.

The results of studies concerning the effect of ultrasonic impact parameters exerted on the characteristics of a formed aerosol are presented. Based on high-speed filming performed under spraying a drop of a model liquid, a qualitative description of changes in the aerosol parameters is given depending on the viscosity of the liquid and the amplitude of ultrasonic oscillations. In the course of computer processing of video fragments, the aerosol concentration, the average size of the droplets, and their motion velocity have been determined.

Синтезирован и структурно охарактеризован новый комплекс кобальта [Co(dppaPh)2(CH3CN)2](BF4)2 (1), где dppaPh = N,N-бис(дифенилфосфино)анилин, и выявлены его структурные особенности по сравнению с описанным ранее комплексом [Co(dppaPh)2(η1-P4)]BF4, содержащим η1-координированную молекулу белого фосфора в координационной сфере. Установлена роль растворителя в процессе кристаллизации комплекса 1: проведение реакции в CH3CN приводит к образованию стабильного октаэдрического комплекса, в котором реализуется координация двух молекул растворителя в аксиальных положениях.

A review of the current state of research on the effect of ultrasonic treatment on the condition of the surface is carried out. Studies are presented in which the relationship between the parameters of the ultrasonic treatment mode and the physical and mechanical properties of the surface is considered. Various types of ultrasonic liquid and solid-state processing are considered. The second part of the review is devoted to cavitation-erosion treatment, ultrasonic surface plastic deformation and combined processes.

The paper considers processes of the electromagnetic radiation propagation at the frequency of 9.027 GHz (corresponding to the wavelength in vacuum of 33.2 mm) in the round-section waveguides of an experimental unit to determine the burning rate of the mixed energy-condensed systems under the high pressure conditions. Qualitative theoretical analysis of the electromagnetic radiation interaction with single metal and contrast dielectric particles in the carrier dielectric medium of a condensed system and arrays of metal and contrast dielectric particles distributed in space was carried out. The paper evaluates the influence of electromagnetic radiation, base material and filler particles on parameters of the resulting standing wave in the microwave unit waveguide for measuring the burning rate of an energy-condensed system, and assesses theoretically the qualitative effect of the filler content on the error in the microwave measurement system. Results of the experimental study of combustion of two model energy-condensed systems, as well as the exemplary model dielectric material (transformer oil) by the microwave method, were analyzed. Study results are the practical justification for introducing the microwave method in diagnosing combustion characteristics of the energy-condensed systems containing particles of the metallized filler

For various methods of obtaining coatings, the general stage of technology is the preparation of the surface for the application of the coating material. The properties of the resulting coating directly depend on the quality of preparation. In the process of obtaining coatings, the most common application of ultrasonic treatment to clean the surface from all kinds of contaminants. However, with a sufficient intensity of processing, ultrasound has a significant effect on the geometric properties of the surfaces of products. Prolonged cavitation action leads to changes in the roughness and sub-roughness of the metal surface. The article discusses the effectiveness of the use of ultrasonic liquid treatment in the preparation of surfaces for coating. The results of studies on the effect of cavitation on the change in roughness, sub-roughness and oil absorption are presented. Revealed an improvement in the adhesion properties of surfaces after ultrasonic liquid treatment.

The possibilities of using the ultrasonic technologies to improve the operational properties of functional coatings are considered. Technological recommendations for the use of ultrasonic technologies at various stages of coating deposition are proposed.

The advantages of ultrasonic spraying technology compared to pneumatic spraying technologies have been examined. The physical-mechanical and geometrical properties of the surface obtained after spraying the paint material by ultrasonic and pneumatic methods were compared.

A composite of graphene oxide (GO) and oleate-protected iron oxide nanoparticles (IONPs) has been developed, synthesized, and characterized by SEM, TEM, AFM, and FTIR spectroscopy. The dispersion of GO/IONPs in an organic medium in the presence of an external magnetic field exhibits a magneto-optical effect that was used to obtain a composite material based on the NPEL-128 amino-cured epoxy resin. The viscosity of the composition was adjusted by adding n-butylglycidyl ether (BGE), the optimal composition was chosen with a BGE content of 30 wt%. The samples were obtained without nanoadditives, with the addition of GO, IONPs, and GO/IONPs particles, the latter were cured without applying a magnetic field, as well as parallel and perpendicular to the direction of the magnetic field. The obtained samples were tested for wear with the determination of the friction coefficient and wear rate, as well as the analysis of the wear profile. It has been established that samples with GO/IONP cured in a magnetic field were subjected to the greatest wear. Conclusions are drawn about the core role of the orientation of GO/IONPs flakes in a magnetic field in the mechanism of wear of polymer nanocomposite samples.

Two-dimensional black phosphorus (BP) has attracted great attention as a perspective material for various applications. The chemical functionalization of BP is an important pathway for the preparation of materials with improved stability and enhanced intrinsic electronic properties. Currently, most of the methods for BP functionalization with organic substrates require either the use of low-stable precursors of highly reactive intermediates or the use of difficult-to-manufacture and flammable BP intercalates. Herein we report a facile route for simultaneous electrochemical exfoliation and methylation of BP. Conducting the cathodic exfoliation of BP in the presence of iodomethane makes it possible to generate highly active methyl radicals, which readily react with the electrode’s surface yielding the functionalized material. The covalent functionalization of BP nanosheets with the P–C bond formation has been proven by various microscopic and spectroscopic methods. The functionalization degree estimated by solid-state 31P NMR spectroscopy analysis reached 9.7%.

Mathematical simulation was applied to evaluating the flame spreading and the flame front speed through the air suspension of boron particles as a function of pressure, excess oxidant ratio, and the particle size. Calculation accounts for a change in heat and mass transfer with a reduction of the particle size from micro-size to nano-scale. The model of flame front propagation through boron particle suspension in air (with account for molecular-kinetic mechanism of heat and mass transfer) allows estimating the normal speed of flame propagation as a function of initial size of boron particles, oxidant excess ratio, and pressure. The conditions were estimated and existence of extremes and flat zones on the curves was justified from a change in heat and mass transfer due to transition from the continuous medium flow to free-molecular flow regime.