


Том 92, № 12 (2018)
- Год: 2018
- Статей: 43
- URL: https://bakhtiniada.ru/0036-0244/issue/view/10355
Physical Chemistry of Hybrid Nanomaterials and Multicomponent Systems
Influence of the Specific Surface Area of CeO2–ZrO2 Supports on the Activity of Pt-Containing Catalysts in the Cinnamaldehyde Hydrogenation Reaction
Аннотация
The maximum yield of cinnamyl alcohol (80%) was achieved on a 1% Pt/CeO2–ZrO2 catalyst based on the support pre-calcined at 400°C with the largest specific surface area (108 m2/g) and the smallest Pt nanoparticle size (4 nm). The dependence of the surface area of cerium-zirconium supports on the thermal treatment conditions and its effect on the activity of supported catalysts was shown.



Effect of Microwave Radiation on the Solvent-Free Synthesis of MOF-199
Аннотация
MOF-199 was synthesized in two ways: mechanochemical and microwave activation. The synthesized materials were characterized by X-ray diffraction and the Klyachko–Gurvich technique of measuring their specific surface areas. Rotational spectra were modeled for compounds representing the most important ligands in the synthesis of MOF-199-like structures: 1,3,5-benzenetricarboxylic acid, 2-methylimidazole, terephthalic acid, and 2,5-dihydroxyterephthalic acid. Based on the resulting data, an explanation was proposed for the abnormal behavior of the 1,3,5-benzenetricarbolxylic acid–copper(II) acetate reaction mixture under conditions of microwave activation and the impossibility of synthesizing MOFs from terephthalic and 2,5-dihydroxyterephthalic acids without a solvent.



Formation of Finely Dispersed Structures in Aluminum Alloys with Niobium in the Presence of Scandium
Аннотация
The possibilities of improving the strength characteristics of alloys based on aluminum and niobium are studied. It is established that the use of scandium allows finely dispersed hardening intermetallide phases to be obtained. The maximum effect of dispersion hardening is observed upon annealing an alloy with the composition Al 99.0 at %, Nb 0.7 at %, and Sc 0.3 at % for 54 h at 300°С.



Effect of Vanadium and Zirconium on the Formation of Metastable Phases in Aluminum and Iron Alloys
Аннотация
Microcrystalline alloys of Al–V, Al–Fe, Al–Fe–V, and Al–Fe–Zr systems are prepared via spinning. The alloys are studied by means of physicochemical analysis. The regions of homogeneity in the resulting supersaturated Al-based solid solutions are determined. The stages of the decomposition of supersaturated solid solutions are studied, along with the effect vanadium and zirconium additives have on the structure and phase composition of rapidly quenched Al and Fe alloys and their mechanical properties, including the effect of dispersion hardening.



Highly Efficient Pt-Catalyst Supported on Mesoporous Ceria-Zirconia Oxide for Hydrogenation of Nitroaromatic Compounds to Anilines
Аннотация
In this work, we have prepared a new catalytic system based on highly dispersed Pt nanoparticles supported on mesoporous ceria-zirconia oxide. The unique ability of the synthesized catalyst to activate hydrogen in the temperature range from –50 to 25°C allows us to provide selective hydrogenation of nitro-aromatic compounds to anilines at room temperature and atmospheric pressure of H2.



Effect of Hydroxyl Groups in a Cation Structure on the Properties of Ionic Liquids
Аннотация
Two series of imidazolium ionic liquids with the bis(trifluoromethylsulfonyl)imide anion were synthesized, which differ by the presence of a hydroxyl group at the ω-position of the alkyl substituent in the cation structure (nC = 2–8). The properties of the liquids were studied by DSC, TGA, and IR and NMR spectroscopy. Their thermal stability was studied, and the melting points, viscosity, and volatility in vacuum were measured. The effect of OH groups in the structure of the ionic liquid on its properties was evaluated.



Conditions for the Formation of Microporous Metal–Organic Framework Mil-53(Al)
Аннотация
Conditions of crystallization are determined for the MIL-53 (Al) (AlOHbdc, bdc = benzene-1,4-dicarboxylate) microporous metal–organic framework. Three major factors responsible for the formation of a pure phase of MIL-53(Al) are identified. These include the temperature (above ~120°С) and the nature of the solvent. It is established through powder diffraction that using microwave radiation for the activation of the reaction mass leads to the formation of a material with higher phase purity, in contrast to preparation techniques that employ conventional heating (hydrothermal synthesis and synthesis under atmospheric pressure).



Modifying the Hydrophobic Properties of Metal–Organic Framework HKUST-1
Аннотация
The possibility is considered of optimizing the hydrophobic properties of metal–organic framework HKUST-1 (Сu2(btc)3, btc = benzene-1,3,5-tricarboxylate) using chloroform as a component of the reaction medium during synthesis. Using this modified technique to prepare the material helps to enhance its textural and structural characteristics.



A New Redox Method for Depositing FeOx on the Surface of Pd(0)/SiO2 Nanoparticles—Catalysts for Selective Phenylacetylene Hydrogenation
Аннотация
A catalyst containing iron oxide particles on the surface of palladium nanoparticles is synthesized for the first time using a redox method of the catalytic reduction with hydrogen. The activity of the catalyst in the selective hydrogenation of phenylacetylene considerably increased, compared to the initial palladium catalyst.



Synthesis of Magnetite Nanoparticles upon Microwave and Convection Heating
Аннотация
Size-dependent properties of magnetite (Fe3O4) nanoparticles, obtained by convection heating and by the microwave method, are compared. Generally, the synthetic procedures involving microwave heating require less time and provide smaller particle sizes and narrower size distribution. Consequently, the specific area of the prepared samples increases. The results are based on the X-ray phase analysis, transmission electron microscopy (TEM), and nitrogen adsorption measurements (Brunauer–Emmett–Teller method).



Dehydrogenation of Propane with СО2 on Supported CrOx/SiO2 Catalysts
Аннотация
A systematic analysis was performed of the physicochemical properties of amorphous silicas (Acros, Degussa, KSKG) and CrOx/SiO2 catalysts prepared from them with 2, 3, 5, 7, and 10 wt % chromium. The supports and catalysts were characterized by BET, XRD, and UV–Vis diffuse reflectance spectroscopy. In the oxidative dehydrogenation of propane with carbon dioxide, the highest propylene selectivity (95%) was observed for the 5% CrOx/SiO2 (Degussa) sample, and the highest propane conversion (53%) was reported on the 5% CrOx/SiO2 (Acros) catalyst. The structure of chromium oxide particles on the support surface was studied by UV–Vis spectroscopy. The catalytic properties were correlated with the state of chromium.



Ring Opening of Naphthene Hydrocarbons under Conditions of Thermal and Microwave Heating
Аннотация
A comparative study of the activity and selectivity of monometallic Ir-containing catalysts in ring opening reactions under conditions of thermal and microwave heating is performed using the example of cyclohexane. The hydrogenolysis of cyclohexane is shown to be possible with microwave activation. It is found that upon microwave heating, iridium-containing catalysts supported on titanium oxide and activated carbon allow 60% selectivity to be reached with respect to ring opening products at 30% conversion of the initial cyclohexane.



Selective Hydrogenation of the C≡C to С=С Bond on Fe-Containing Catalysts
Аннотация
Supported monometallic Fe/SiO2 and bimetallic Fe–Cu/SiO2 catalysts were synthesized by incipient wetness impregnation. The synthesized catalytic systems were studied in selective hydrogenation of phenyl-acetylene with molecular hydrogen under mild reaction conditions (H2 pressure 1.3 MPa, 80–110°C). The catalytic properties of monometallic samples depend on the conditions of thermal treatment. The best results on the selectivity of styrene formation (78%) at complete conversion of phenylacetylene were obtained on the reduced sample, in which iron was in the metal state. The modification of the iron oxide phase with copper (0.4 wt %) makes it possible to exclude the stage of reduction of FeOx to Fe0 in hydrogen at high temperatures and to retain high catalytic activity and attain styrene selectivity of 78%.



Catalytic Activity of Cu and Cu–Fe Hydrosilicates in Hydrogenation with Molecular Hydrogen
Аннотация
Deposited copper hydrosilicates are synthesized using KSKG industrial silica gel. The hydrosilicates are modified with Fe2+ ions. Their catalytic activity and high selectivity in the hydrogenation of dinitrobenzene is shown to yield nitroaniline and phenylenediamine under mild conditions at 170°C and a hydrogen pressure of 1.3 MPa. As an example, C–C triple bond in phenylacetylene is hydrogenated for the first time on such materials using molecular hydrogen under relatively mild conditions.



Chemical Thermodynamics and Thermochemistry
Gibbs Calculations of the Equilibrium Surface Tension in a Vapor–Liquid System
Аннотация
A correct way of calculating the equilibrium surface tension of planar and curved vapor–liquid interfaces is formulated for the first time according to Gibbs (i.e., as the excess free energy in the region of immiscible phase transitions). Calculations are performed using a modified lattice gas model that reflects a discrete–continuous distribution in the space of mixture components. The discrete size scale is associated with regions of around the size of a molecule that form the cells of the lattice structure. The continuous scale corresponds to the intermolecular motion of components inside the cells. The intermolecular interactions of comparable components are considered in a quasi-chemical approximation that describes direct correlations. It is shown that considering only the discreteness of the molecular distribution on a rigid lattice does not provide simultaneous satisfaction of two special conditions of chemical and mechanical equilibria for any degrees of interface curvature, and that the conditions of phase partitioning are insufficient for unambiguous calculations of the surface tension. The condition for the complete equilibrium of two phases must be supplemented with the conditions of the local mechanical and chemical equilibria at each point of the boundary transition region, and the local pressure value must be adjusted to the local value of the chemical potential.



Thermodynamics of the Stepwise Dissociation of N-Methyliminodiacetic Acid
Аннотация
The heat effects of the protolytic equilibria of N-methyliminodiacetic acid at 298.15 K and the ionic strengths of 0.1, 0.3, 0.5, 1.0, and 1.5 (KNO3) are determined via direct calorimetry. The standard thermodynamic characteristics of the studied equilibria are calculated. The results are compared to the corresponding data for related compounds.



Thermodynamic Description of the Nonexchange Sorption of Substances by Ion Exchangers
Аннотация
Based on the stoichiometry of absorption, a thermodynamic approach is proposed for describing the nonexchange sorption of substances with ion exchangers from individual solutions and mixtures. This approach is applied to describe the absorption of amino acids using the sorption of tryptophan and hystidine with anion exchangers AV-17-2P in Cl form as an example. Integral and differential characteristics of nonexchange sorption in these systems are described.



Chemical Kinetics and Catalysis
Kinetic Features of Gas Ignition upon Heating
Аннотация
Using hydrogen oxidation as a model reaction, it is shown that the ignition of combustible gases upon heating in the region of atmospheric pressure is caused by a chain avalanche reinforced by self-heating of the reaction mixture, which becomes marked as combustion develops. The functional character of the temperature dependence of the rate of the chain reaction outside the region of ignition differs fundamentally from the Arrhenius law.



Catalytic Conversion of Glycerol into Aromatic Hydrocarbons, Acrolein, and Glycerol Ethers on Zeolite Catalysts
Аннотация
The effect of the nature of zeolite catalysts H-ZSM-5, H-BETA, and SAPO-34 on the activity and selectivity in the conversion of glycerol into aromatic hydrocarbons, acrolein, and oxygenates (various glycerol ethers) was studied. H-ZSM-5 was found to be the most effective catalyst for the conversion of glycerol into aromatic hydrocarbons and mono-, di-, and trisubstituted glycerol ethers with methanol and isobutylene. These products are effective gasoline additives increasing its octane number. Zeolite SAPO-34 shows the lowest activity in aromatization and alkylation reactions; the main product formed on this catalyst was acrolein.



Coherent-Synchronized Biomimetic Monooxidation of Cyclohexane by Hydrogen Peroxide
Аннотация
Activity and selectivity of heterogeneous biomimetic catalysts per-FTPhPFe(III)OH/Al2O3 and PPFе(III)OH/Al2O3 towards particular compound have been studied during the process of gas-phase oxidation of cyclohexane and its mixture. Varying process parameters (temperature, H2O2 concentration, contact time) has provided an opportunity to obtain a common understanding of the active influence of these catalysts during the oxidation of cyclohexane in the mixture with its derivatives, where their selective action towards cyclohexane has also been observed. On the basis of the experimental research of the process of cyclohexane monooxidation, it has been found out that a complex reaction takes place on the biomimetic catalyst. This complex reaction consists of parallel-sequential monooxidation and oxidative dehydrogenation reactions that are coherently synchronized with H2O2 decomposition reaction. Possible mechanisms of cyclohexane biomimetic conversion to the target products are presented. The unity of the mechanisms of acid-base catalysis and the redox system based on the principle of CBR (chain of bond rearrangement) which is typical of enzymatic catalysis can be traced during this conversion. Depending on the process parameters, it is possible to consciously control the direction of the monooxidation reaction and its rate.



Theoretical Study of Copper Acetonitrile Effects on Parr Functions Indices and Regioselectivity Using Density Functional Theory (DFT)
Аннотация
Copper-catalyzed azide–alkyne cycloaddition (CuAAC) is a straightforward way for making covalent connections between building blocks containing various functional groups. It is widely used in organic synthesis, medicinal chemistry, polymer chemistry, and bioconjugation applications. Using copper acetonitrile as catalyst for click reactions (CuAAC) lead to a non-concerted reaction, and affect Parr functions indices to determine the polar sites, therefore predict the favorable regioisomer (1,4-regioisomer) and explain the contradiction obtained to the experimental results. The huge difference of activation barriers between catalyzed and uncatalyzed reaction indicate that is a selective reaction.



Rhodium Catalyst–Ionic Liquids Interaction by X-ray Photoelectron Spectroscopy Data
Аннотация
We investigate the Schrock–Osborn catalyst, [Rh(COD)(PPh3)2][PF6], in a series of ionic liquids by XPS. The electronic environment of the rhodium centre is demonstrated. The subtle change of the electronic environment of the rhodium centre due to the catalyst-ionic liquids interaction is revealed based upon Rh 3d binding energy. It suggests that the anion of ionic liquids can have significant impact on the electronic environment of the rhodium centre.



Oxidation of Methyl Propanoate by the OH Radical
Аннотация
Atmospheric oxidation of methyl propanoate (MP) by the OH radical has been performed using density functional theory (BMK, BBIK) and ab initio (MP2, CBS-QB3) calculations. The thermodynamic and kinetic parameters are calculated. Three channels have been discussed. These reactions occur through low energy barriers of 3.2–4.3 kcal/mol. The energy barriers increase in the order α < µ < β at CBS–QB3. However, BMK shows slightly different order. Rate constants and branching ratios reveal that the H-abstraction from Cα is as the dominant reaction over the whole temperature range of 200–300 K, with a competition from Cβ channel at lower temperature. The BB1K data reproduce the available experimental rate constant.



Physical Chemistry of Solutions
Thermodynamics of the Dissolution of Nitrilotrimethylphosphonic Acid in Water
Аннотация
The enthalpies of dissolution of crystalline nitrilotrimethylphosphonic acid С3Н12NO9Р3 (NTPA) in water at 298.15 K are determined calorimetrically. The standard enthalpies of formation of nitrilotrimethylphosphonic acid and products of its stagewise dissociation in aqueous solutions are calculated.



Specific Molecular Interactions of Dihydropyridine Moiety in Polar and Non-Polar Solvents at Various Concentrations and Temperatures 303–318 K on Ultrasonic Data
Аннотация
Ultrasonic studies of compounds of dihydropyridine series in polar and non-polar solvents at various concentrations and temperatures 303–318 K. Density and ultrasonic velocity and different thermo-acoustical parameters measured. Rao’s constant, molar volume, Wada’s constant, isothermal compressibility reported with the help of these data using standard formulae. Ethanol and DMF selected as polar and non-polar solvents respectively. The variation in thermoacoustical parameters with temperature and concentration shows that the solute–solute molecular interaction takes place in solution which is more in DMF.



Extraction of Cobalt(II) from Sulfate Medium with Substituted Salicylideneanilines
Аннотация
The liquid-liquid extraction of cobalt(II) from sulfate media (Na2SO4) with substituted salicylideneanilines (SAN) is investigated. The stoichiometry of the extracted complexes formed in the organic phase is evaluated. It was found that the cobalt is coordinated with three ligands (L), and composition of the extracted complex is: CoL2HL and cobalt is coordinated with two ligands (L) in case of substituted SA as CoL2. The values of the extraction constants were calculated and analyzed in terms of the nature of the substituents.



Phase Diagrams of Ternary and Quaternary Systems Containing Heptane, Toluene, Dimethylsulfoxide, Methanol, and Ethanol at 298.15 K
Аннотация
Liquid–liquid equilibrium of the ternary and quaternary systems (heptane + toluene + dimethyl sulfoxide), (heptane + toluene + dimethylsulfoxide + methanol), (heptane + toluene +dimethylsulfoxide + ethanol) were studied at 298.15 K and atmospheric pressure. The thermodynamic consistency of the experimental data was verified by Othmer-Tobias and Hand correlations. Selectivity and solute distribution ratio were calculated and experimental data were correlated by the nonrandom Two-Liquid activity coefficient model. Correlated results are in good agreement with experimental data.



Structure of Matter and Quantum Chemistry
Optical Properties and Model of the Electronic and Spatial Structure of Hypercrosslinked Polystyrene
Аннотация
A number of hypercrosslinked polystyrene networks are studied. The networks are obtained via additional crosslinking of granules of styrene copolymer with 0.5% divinylbenzene (0.3–0.5 mm) and microgranules with 1% divinylbenzene (3.5 µm) using monochlorodimethyl ether to densities of crosslinking from 60 to 500%. It is found that as the degree of crosslinking grows, the absorption in the electronic spectrum of the polymer extends to the visible region, and the granules change color (toward as dark as black); this phenomenon is much less expressed for microgranules and milled materials. For a consistent explanation of these two observations, assumptions are made about the appearance and increase in the contrast of density fluctuations of a tracery hypercrosslinked network and light scattering on such micro-inhomogeneities in the volume of particles of the compared series of polymers.



The First Principles Calculations of the Interaction between Li, Na, and K Atoms and Silicene
Аннотация
Interaction between Li, Na, and K atoms and autonomous silicene is investigated using the density functional theory. The energies of adsorption and bond distances of Si–Me for different positions of adsorbed alkali-metal atoms are calculated. The band structure of the silicene–Me systems in a generalized gradient approximation is determined. It is found that metallic conductivity can result from either substituting an atom of Si for an atom of Li, or the one-sided complete adsorption of silicene by atoms of Na. It is shown that the adsorption of atoms of K does not result in the formation of metallic conductivity, but it does ensure lower values of the energy gap than that obtained via the adsorption of atoms of Li or Na.



Theoretical Study of NO Linkage Isomers in a Rhenacarborane Nitrosyl Complex
Аннотация
This research demonstrates the stability of linkage isomers of [1,2-H2-3,3-(CO)2-3-X-closo-3,1,2-ReC2B9H9]; X = η1-NO, η2-NO, η1-ON by the use of MPW1PW91 quantum method. The singlet and triplet states were considered for studied complexes. Structural parameters, HOMO-LUMO gap, energies of frontier orbital and vibrations modes of CO and NO ligands were explored in linkage isomers in two states of spin. Moreover, the interaction of bonding between the NO+ with [1,2-H2-3,3-(CO)2-closo-3,1,2-ReC2B9H9]– fragment, NO– and [1,2-H2-3,3-(CO)2-closo-3,1,2-ReC2B9H9]+ fragment was analyzed using the energy decomposition analysis (EDA). Nucleus-independent chemical shift (NICS) values were determined at the center of carborane indicate aromaticity of cage.



Molecular Dynamic Study of the Behavior of Confined [BMIM][PF6] Ionic Liquids: Pore Size Dependence
Аннотация
This work aimed to investigate the structural and dynamical properties of ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) confined between two parallel and flat Au sheets. Thus, molecular dynamic (MD) simulations were performed for different pore sizes including 1.2, 2.0, and 3.0 nm at 300 K. The results showed that the behavior of confined ILs are totally depart from the bulk ones. Further, it is should be noted that, these differences greatly depended on the pore size. Our results suggest that the interactions between Au pore walls and the ILs are obviously strengthened by the decrease of the pore sizes.



Physical Chemistry of Nanoclusters and Nanomaterials
Patterns of the Formation of Antimicrobial Micro/Nanocomposites during the Oxidation of Bimetallic Al/Zn Nanoparticles
Аннотация
Porous composites of different phase composition are synthesized via oxidation in a water–ethanol mixture of bimetallic Al/Zn nanoparticles obtained through a joint electrical explosion of aluminum and zinc wires in an argon atmosphere. It is found that the oxidation of aluminum and the formation of boehmite nanosheets proceed in solutions containing 7‒20 wt % of water. At water contents over 20 wt %, the almost complete oxidation of aluminum is followed by the onset of zinc oxidation, resulting in the formation of composites containing boehmite nanosheets and hexagonal plates enriched with zinc oxide. Composites synthesized in this way display high antimicrobial activity against bacteria, due mainly to the release of Zn2+ ions into the solution. The greatest antimicrobial activity is observed in composites that simultaneously contain AlOOH, Al, ZnO, and Zn phases. The strong migration of Zn2+ ion is due to the structure of these composites, in which the active zinc surface grows as a result of the availability of ZnO plates located between the boehmite nanosheets. The boehmite nanosheets ensure stability of the composite structure and electrostatic interaction with bacteria.



Hollow Graphene-Based Microspheres Adsorbents for Removal of Gaseous Formaldehyde
Аннотация
Two type of hollow graphene microspheres were investigated for the adsorption performance of gaseous formaldehyde. Hollow gently reduced graphene oxide microspheres (HgRGOS) were synthesized by using the polystyrene microspheres as sacrificial template and gently reducing graphene oxide with NH2NH2. Hollow amine modified graphene microspheres (DETA-HgRGOS) were synthesized by DETA-treatment following the before-mentioned steps. The materials were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffractometry, Fourier transform infrared and X-ray photoelectron spectroscopies. This was followed by formaldehyde adsorption tests. The results showed that HgRGOS and DETA-HgRGOS were characterized to have adsorption capacities of 24.54 and 17.18 mg/g. The amine-modified material can interacts with HCHO more easily than the material eith carboxyl and epoxy groups on the surface. The reaction mechanism was discussed according to FTIR and XPS analysis.



Physical Chemistry of Surface Phenomena
A Model of Solid-Phase Synthesis in Binary Powder Mixtures with Allowance for Caking
Аннотация
A mathematical model of solid-phase chemical synthesis in a binary powder mixture is constructed and studied with allowance for the shrinking of the mixture and the change in the reaction surface as a result of particle caking. Relations are obtained to estimate the number of similar and dissimilar interparticle contacts. Depending on the parameters of the mixture (the stoichiometric ratio between components, the particle size ratio, and the porosity), different modes are revealed that affect the rate of chemical transformation. The optimum conditions for an intense chemical interaction are determined.



Adsorption from Neutral Solutions of Sodium Alkyl Phosphonates on Zinc and Its Passivation
Аннотация
Ellipsometry is used to study the adsorption of the sodium salt of decyl phosphonic acid (SDP) on zinc in a borate buffer solution with pH 7.4. It is found that adsorption of SDP is described by the Tyomkin equation on both oxidized and reduced zinc surfaces, and its adsorption activity on the reduced surface is higher. The inhibiting effect the sodium salt of dodecyl phosphonic acid (SDDP) has on zinc is studied in a chloride-containing borate buffer solution with pH 7.4. It is shown that SDDP has better passivating ability than SDP. The passivating effect of SDDP depends on a certain threshold concentration of the inhibitor. Increasing the alkyl phosphonate concentration and the duration of electrode conditioning in the solution enhances the protective properties of films formed when it is present on zinc.



Enhanced Adsorption of SO2 Molecule on Al- and Si-Doped Pyridinic Nitrogen Doped Graphene
Аннотация
The adsorption properties of SO2 molecule on the surface of pyridinic nitrogen doped graphene (4NG), M/4NG and M/2NG (M = Al, Li, Si) are investigated using density functional theory. The adsorption energies have been calculated for the most stable configurations of the molecule on the surface of 4NG, M/4NG, and M/2NG. It is found that M/4NG (M = Al, Si) have significant adsorption energies than that of pyridinic nitrogen doped graphene and M/2NG (M = Al, Si). The doped Li atom did not enhance the interactions between the 4NG and SO2. Furthermore, connecting distance and net electron transfers give the evidence that the SO2 stay on M/4NG (M = Al, Si) by chemisorption. Significant changes in density of states (DOS) show the existing of noteworthy orbital hybridization between SO2 and M/4NG–SO2 (M = Al, Si) during adsorption process which is proving to strong interaction while there is no evidence for hybridization between the SO2 molecule and 4NG. Compared with 4NG, Al/4NG, and Si/4NG may be promising adsorbent for practical applications.



Preparation and Characterization of Carbonate-type Mg–Al Layered Double Hydroxides by Ion Exchange Resins
Аннотация
Carbonate-type Mg–Al layered double hydroxides were successfully prepared using ion exchange resins. Based on XRD patterns, 8 h and 40°C were considered to be an optimal reactive condition to obtain pure Mg6Al2(OH)16CO3 · 4H2O. SEM showed a sheet structure of samples, the largest diameter and the mean thickness were roughly 2 µm and 100 nm, respectively. EDS datas indicated that temperature was one of key influence factors to obtain the excellent composite materials. FT-IR and TG-DSC results further confirmed that the proposed method was feasible and effective to prepare carbonate-type Mg–Al layered double hydroxides.



Colloid Chemistry and Electrochemistry
Effect of Hydrocarbonates and Chlorides on the Photodestruction of Bisphenol A
Аннотация
The effect hydrocarbonates and chlorides, the most common anions in natural and waste waters, on the oxidation of bisphenol A by persulfate activated with iron ions and simulated solar radiation is studied. It is established that hydrocarbonates have an inhibiting effect due to deactivation of Fe2+ ions and non-target expenditure of the in situ generated reactive oxygen species by reactions with hydrocarbonates. It is found that chlorides have a promoting effect: the reaction of bisphenol A oxidation is accelerated by 1.25–1.4 times, and the degree of mineralization grows by 18–44%. The established patterns are in good agreement with the existing data for real aqueous systems (surface waters of lakes Baikal and Gusinoe).



Equilibria in a ZnCl2–H2O–NaOH System, According to Data from Potentiometric Titration, and Selecting Conditions for the Hydrochemical Synthesis of ZnS and ZnSe Films
Аннотация
Equilibrium processes that occur in the ZnCl2–H2O–NaOH system are studied via the potentiometric titration of zinc chloride in the 0.00006–1.01 mol/L range of concentrations. Based on mathematical simulations, a number of polynuclear structures and soluble phases are identified in the system. Values of the instability constants of complex forms and the constants of the dynamic equilibria of weakly soluble zinc compounds are calculated, along with their stoichiometric compositions and areas of sustainable existence. Refined boundary conditions are determined, along with areas of the formation of ZnSe and ZnS when they are precipitated using sodium selenosulfate and thiourea, respectively. ZnSe and ZnS layers around 1000 and 200 nm thick are obtained via hydrochemical deposition on glass-ceramic substrates. Based on electron microscopy data, it is concluded that the layers consist of spherical aggregates with mean sizes of around 350–450 nm for ZnSe and 50–200 nm for ZnS, generated from primary particles with sizes of around 20–60 and 20–30 nm, respectively.



Photochemistry and Magnetochemistry
Synthesis and Characterization Performance of Amphiphilic ZnO, a Novel Photocatalyst Suitable for Degradation of Contaminants in Oil–Water Two Phase System
Аннотация
Amphiphilic zinc oxide (ZnO) was successfully prepared by modifing neat ZnO with silane coupling reagent KH-570. The modified ZnO and neat ZnO were characterized by measurement of the lipophilic degree value; Fourier transformed infrared spectroscopy (FT-IR), ultraviolet-visible (UV–Vis), X-ray diffraction (XRD). The results showed that KH-570 was successfully coated on surface of the neat ZnO, as a result, the modified ZnO was amphiphilic. Compared with neat ZnO, amphiphilic ZnO has a better compatibility with the organic solvent and its photocatalysis ability for oil degradation was enhanced by 28%. The improved oil degradation performance of amphiphilic ZnO can be explained by its hydrophobic property, which is benefit for absorbing oil in water.



Biophysical Chemistry
Solubilization of Biologically Active Heterocyclic Compounds by Biocompatible Microemulsions
Аннотация
Microemulsions based on biocompatible components with high water content are applied to increase the solubility of medicinal drugs of the heterocyclic series indomethacin and 1-[5-(4-chlorophenyl)-3-phenylpyrrole-2-yl]benzimidazole-2(3H)-one (PBI). The solubilizing capacity is characterized quantitatively via spectrophotometry. It is shown that four-component microemulsion water/oleic acid/Tween 80/ethanol increases the limits of indomethacin solubility by more than two orders of magnitude, and that of PBI by more than three orders relative to water.



Short Communications
Effect of Solvation on the Acid–Base Equilibria of Succinic Acid in Н2О–EtOH and Н2О–DMSO Solutions
Аннотация
The Gibbs energies of transferring succinic acid from water to aqueous ethanol and aqueous dimethylsulfoxide solvents are determined according to solubility. An increase in the negative values of the Gibbs energy upon moving from water to aqueous–organic solvents is observed. The effect the composition of solvents has on the acid–base properties of succinic acid is analyzed using the thermodynamic solvation approach. It is shown that the main contribution to the shift of the acid–base equilibria of succinic acid in aqueous ethanol and aqueous dimethylsulfoxide comes from the weakening of the solvation of its deprotonated forms.



Proton/Metal–Ligand Stability Constants of Complexes of Sr(II), Cr(II), and Al(III) with N-Phthaloyl Aminoacid and Benzimidazole Derivatives in Dioxane–Water Mixture
Аннотация
Formation of complexes Sr(II), Cr(II), and Al(III) with ligands (1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)acetic acid (L1), 2-(1-(2-(4-nitrophenyl)-1H-benzo[d]imidazol-1-yl)-1-oxobutan-2-yl)-2,3-dihydroinden-1-one(L2) and 2-(2-(2-(4-chlorophenyl)-1H-benzo [d] imidazol-1-yl)-2-oxoethyl)isoindoline-1,3-dione (L3) investigated using pH metric technique in 70% dioxane-water mixture. Proton ligand formation number and metal-ligand formation number determined. Proton-ligand stability constants pK values and metal – ligand stability constants log k values evaluated using half integral method. It indicates that Sr(II), Cr(II), and Al(III) metal ions formed 1 : 1 and 1 : 2 complexes with the ligands L1, L2, and L3. These can be of interest for specialists in the field of coordination chemistry.


