JournalTOCs

Theoretical and Experimental Chemistry
Journal Prestige (SJR): 0.247

Citation Impact (citeScore): 1
Number of Followers: 0

Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1573-935X - ISSN (Online) 0040-5760
Published by Springer-Verlag

[2468 journals]

Photovoltaic Properties of Thiophene-Containing Derivatives of
4,5-Diazafluorene and Their Ruthenium(II) Complexes
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  Abstract: It is shown that the derivatives of 4,5-diazafluorenone-9-hydrazone containing thiophene and aldehyde anchor groups, as well as mixed-ligand Ru(II) complexes with these dyes and bipyridine, have the properties of sensibilizers of TiO2-based photovoltaic cells. The power conversion efficiency (η) in such photovoltaic elements under simulated 100 mW/cm2 solar radiation is in the range of 0.25-0.48%. The value of η in the case of compounds, bearing thiophene-2,5-dicarbaldehyde fragment as an anchor, is almost two times higher compared to the analogues, containing non-substituted thiophene fragment.
  PubDate: 2023-11-03
Effect of Co2 Content on Biogas-to-Syngas Conversion for Methanol
Production
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  Abstract: The influence of carbon dioxide concentration in biogas on the composition of its reforming products has been studied to achieve optimal methanol synthesis conditions. A model of the biogas reforming stage is proposed. An optimal concentration of carbon dioxide in biogas essential for maximizing methanol production has been found. The effect of geometric characteristics of the mixing device on the homogeneity of the reacting flow, which is a critical for the process performance, has been established.
  PubDate: 2023-10-31
Photocatalytic Conversion of Lignin in the Presence of Titania and Iron
Titanate Films
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  Abstract: The photocatalytic conversion of lignin, obtained from camelina (Camelina sativa), over titania and iron titanate films has been studied with analysis of the products using laser desorptiopn/ionization and high-performance liquid chromatography. The photocatalytic reaction over titania films leads to the formation of the mixture of compounds, such as phenol, vanillic acid, resorcinol, and p-coumaryl alcohol. In the presence of iron titanate films, the predominant reaction products are vanillic acid and p-coumaryl. The highest antioxidant activity has been revealed in the case of lignin conversion products obtained over nitrogen-containing iron titanate films under visible light exposure.
  PubDate: 2023-10-31
Functionalization of the Surface of Montmorillonite with Cationic
Oligourethane Capable of Diisocyanate Addition
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  Abstract: A method of montmorillonite modification with polar oligourethane containing reactive amino groups has been developed. It is shown that functionalized montmorillonite is capable of adding aromatic and aliphatic diisocyanates, as well as sequential addition of aromatic diisocyanates and glycerol, which is essential for montmorillonite application as filler for polymer materials. According to wide-angle X-ray scattering, interlayer distance d001 of montmorillonite in the obtained samples varies depending on nature of oligomer macromolecules in the interlayer space that is explained with different conformation and orientation of aromatic and aliphatic oligourethane fragments.
  PubDate: 2023-10-31
Effect of the Composition of the Zeolite Framework of Natural
Clinoptilolites on the Exchange of Cations Na+ On Ca2+
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  Abstract: The effect of the zeolite framework composition on the selectivity and thermodynamic parameters of ion exchange is studied for the exchange reaction of Ca2+ cations on Na-forms of clinoptilolites from nine deposits of Central and Southeast Europe, Northeast Asia, and North America. An increase in the thermodynamic affinity of Na-forms towards Ca2+ cations is shown with a decrease in the Si/Al ratio in their zeolite framework.
  PubDate: 2023-10-31
Catalytic Properties of Rh-Containing Carbon Dots on SiO2, Al2O3, and ZrO2
Oxide Supports in the Glycerol Conversion
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  Abstract: It is shown that deposition of Rh-CD (CDs are carbon dots)onto SiO2, Al2O3, and ZrO2 oxide supports contributes to the appearance of the catalytic activity in the process of glycerol conversion. It is established that acrolein and acetaldehyde are oxygen-containing products in this reaction system. It is found that the yield of reaction products increases when using a support with a smaller specific surface area, which is caused by an increase in the surface concentration of acid sites.
  PubDate: 2023-10-28
Carbonized Polyaniline as a Catalyst for Hydrogenation with Molecular
Hydrogen of Organic Substrates with C=C Double Bond and Nitro Group
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  Abstract: Nitrogen-doped carbon, which is characterized by a large surface area and the presence of micro- and mesopores, has been obtained by pyrolysis of polyaniline (emeraldine base) in a reducing atmosphere. It is found that the surface layer of such material contains nitrogen in pyridinic, pyrrolic, and quaternary configurations, as well as hydroxyl and carbonyl groups. It is shown that carbonized polyaniline reveals catalytic properties in the processes of gas-phase and liquid-phase hydrogenation with molecular hydrogen of organic substrates containing C=C double bond and nitro group (ethylene, α-methylstyrene, p-nitrotoluene) are revealed.
  PubDate: 2023-10-28
Clusteroluminescence of Unconjugated Polymers: A Review
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  Abstract: The current state of research on non-conventional luminescence of unconjugated polymers, which is caused by the occurrence of through-space conjugation due to the overlapping of electronic orbitals of atoms in aggregates formed at high concentrations of substances in solutions or the solid state, is considered. The luminescent properties of different types of polymers containing oxygen, nitrogen, sulfur, silicon, boron, phosphorus is analyzed. The possibilities of the practical applications of polymer cluster luminophores in the fields such as ecosystem monitoring, medicine, biology, encryption, forensics, and optoelectronics are shown.
  PubDate: 2023-08-02
  DOI: 10.1007/s11237-023-09768-3
Obtaining, Structure, and Antimicrobial Properties of Nanocomposite
Coatings Based on Polyurethane and Silver Nanoparticles
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  Abstract: A new method of obtaining of antimicrobial coatings based on segmented polyurethanes and silver nanoparticles (SNP) stabilized by an ionic liquid is proposed. The effect of silver nanoparticles on the structure and characteristics of the obtained materials have been studied using X-ray scattering, electron microscopy, infrared spectroscopy, differential scanning calorimetry, and the microbiological method of diffusion in agar. It is established that in the polymer matrix, SNPs with sizes from 7 to 19 nm are formed, and their size depends on the content of the stabilizer. The obtained nanocomposite coatings exhibit high antimicrobial activity against bacteria (S. aureus, E. coli) and fungi (C. albicans).
  PubDate: 2023-08-01
  DOI: 10.1007/s11237-023-09772-7
Obtaining of Luminescent Sulfur Nanoparticles in the
L-Cysteine–Citrate–Sodium Sulfide System
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  Abstract: An obtaining of sulfur nanoparticles by hydrothermal method in aqueous solution of L-cysteine, citrate ions, and sodium sulfide is proposed. The optical properties of the obtained sulfur nanoparticles have been studied by UV-Visible absorption and photoluminescence spectroscopies. Transmission and scanning electron microscopies and atomic force microscopy indicate that sulfur nanoparticles are quasi-spherical, their diameter depends on heat treatment time reaching an average size of 28 nm after 8 h of heating at 378 K. The nanoparticles exhibit photoluminescence in the range from 388 to 515 nm depending on the excitation wavelength. The obtained colloid systems have lasting sedimentation stability and high photoluminescence intensity, which make them promising for further wide application.
  PubDate: 2023-07-31
  DOI: 10.1007/s11237-023-09771-8
Obtaining of Silver Nanoparticles in the Presence of Quercetin and Rutin
Flavonoids
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  Abstract: The peculiarities of the formation and stabilization of silver nanoparticles (NP) in the presence of quercetin and rutin during chemical (NaBH4), thermal (at 90°C) and photochemical reduction of Ag+ ions have been studied considering the ratios of the components. It is shown that the reduction of Ag+ with the formation of silver nanoparticles with size of 50-90 nm occurs most efficiently in the presence of quercetin under the action of UV irradiation. The stabilization of Ag NP occurs due to complexation of flavonoid molecules with the silver ions on the surface of nanoparticles. The obtianed binary colloid composites flavonoid–Ag may be used in medicine as anti-inflammatory and bactericidal agents of prolonged action.
  PubDate: 2023-07-29
  DOI: 10.1007/s11237-023-09774-5
Photocatalytic Activity of Electrochemically Formed Ag2O in the Process of
CO2 Reduction with Water Vapor Under the Effect of Visible Light
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  Abstract: Film-like Ag2O coatings have been obtained using electrochemical method, and their photoelectrochemical and spectral properties have been studied. The photocatalytic behavior of these samples in the process of reduction of carbon dioxide with water vapor has been studied. The possibility of formation of a number of organic compounds (acetaldehyde, acetone, isopropyl and ethyl alcohols, methane) upon irradiation of the systems with visible light has been established.
  PubDate: 2023-07-29
  DOI: 10.1007/s11237-023-09770-9
Influence of Cerium and Stibium Additives on Sensitivity of Semiconductor
Sensors Based on Nanosized SnO2 to Hydrogen
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  Abstract: Semiconductor materials based on SnO2 with different contents of cerium and stibium have been obtained. Their phase compositions, particle sizes and sensitivities of semiconductor sensors based on them to hydrogen have been studied. It is found that introduction of cerium into the material contributes to reduce the sizes of SnO2 nanoparticles. Changes in the values of the sensor responses to hydrogen are explained by influence of catalytic activity of cerium and the competing effect of the introduced stibium on conductivities of the materials.
  PubDate: 2023-07-29
  DOI: 10.1007/s11237-023-09773-6
Luminescence Properties of K2Bi(PO4)(MoO4):Gd,Eu Solid Solutions
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  Abstract: Solid solutions K2Bi(PO4)(MoO4):Gd,Eu containing from 0.1 to 30 mole% of europium(III) and 0.1 mole% of gadolinium(III) have been prepared by conventional solid state reaction. The samples are characterized by X-ray powder diffraction method, IR and luminescence spectroscopies. It has been shown that doping with Eu3+ does not affect the symmetry of the layered framework. At room temperature, all the studied samples are characterized by intense red photoluminescence, which is associated with 5D0→7F0-4 emission transitions in Eu3+ ions. Due to the absence of concentration quenching and color characteristics, K2Bi(PO4)(MoO4):Gd,Eu has prominent prospects for application as a red phosphor.
  PubDate: 2023-07-28
  DOI: 10.1007/s11237-023-09769-2
Catalytic Hydrodehalogenation of Haloarenes with Hydrogen and
Hydrogen-Containing Compounds: A Review
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  Abstract: New catalytic methods for the hydrodehalogenation of haloarenes with hydrogen and hydrogen-containing reagents (metal and non-metal hydrids, organic hydrogen-containing compounds, etc.), which are essential for fine organic synthesis and neutralization of toxic production waste and persistent organic pollutants. The paper focuses on such catalysts as complexes of stable heterocyclic carbenes, transition metals, and nanosized metal particles and their composites, as the most promising for industrial chemistry. Catalysts with particularly high efficiency have been highlighted.
  PubDate: 2023-07-01
Photocatalytic Hydrogen Evolution from Solutions of Benzyl Alcohols Under
the Action of Visible Light with the Participation of Crystalline
Graphite-Like Carbon Nitride
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  Abstract: It is established that the effeciency of the hydrogen evolution from water–acetonitrile solutions of benzyl alcohol and a number of its derivatives under the action of visible light with the participation of crystalline graphite-like carbon nitride increases when electron-donating ability of the substituent in the para position of benzyl alcohol increases. The highest H2 evolution rate, 720 μmol·h–1·g–1 (quantum yield Φ = 22% at 405 nm), is achieved in solutions of 4-methoxybenzyl alcohol in the presence of 0.1 M HCl at 40 °C.
  PubDate: 2023-05-20
  DOI: 10.1007/s11237-023-09762-9
Catalytic Benzoylation of Alanine in Two-Phase Water–Dichloromethane
System
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  Abstract: The inverse phase transfer process of catalytic benzoylation of α-amino acids (on the example of alanine) in a two-phase water–dichloromethane system in the presence of pyridine derivatives as catalysts is investigated. The effect of the initial concentration of alanine, its form in solution, and the initial catalyst concentration on the reaction rate and the composition of the products is studied. It is established that using 4-methyl- and 4-methoxy pyridine N-oxides combined with a double excess of the sodium salt of alanine makes it possible to obtain 2-benzamidopropionic acid with a yield of more than 80%.
  PubDate: 2023-05-19
  DOI: 10.1007/s11237-023-09763-8
Effect of Modifying Additives of Molybdenum and Tungsten Compounds on the
Catalytic Properties of MgO-Al2O3 in the Process of Gas-Phase Conversion
of Ethanol Into 1-Butanol
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  Abstract: The regulation of redox and acid–base properties of MgO-Al2O3 systems has been carried out during the synthesis by introducing bifunctional additives of molybdate and tungstate ions. Doping with Mo and W compounds leads to an increase in the activity of Mg-Al-oxide catalysts and the selectivity of 1-butanol formation in the ethanol condensation process due to an increase in the concentration of the sites of ethanol dehydrogenation and acetaldehyde aldol condensation.
  PubDate: 2023-05-19
  DOI: 10.1007/s11237-023-09764-7
Influence of Chemical Structure of Fluorinated Surfactants on the
Air/Water Interface Properties
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  Abstract: The formation heats for a number of gemini fluorocarbon surfactants have been estimated using density functional theory (DFT), the values of air/water interface formation energies (IFE) have been compared. It is shown that the fluorocarbon surfactants can efficiently reduce the surface tension of the air/water interface. One of the representatives of the surfactants, possessing the highest IFE value (in absolute value), has been prepared and its critical micelle concentration and the corresponding surface tension have been experimentally determined.
  PubDate: 2023-05-19
  DOI: 10.1007/s11237-023-09767-4
Influence of Structure on Lifetime of the Excited State of New
Heptamethinecyanines Based on Benzo[cd]Indole
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  Abstract: It is shown that new benzo[cd]indole-based heptamethinecyanines (HMCs) have an ultrashort lifetime τ of the photoexcited state and a high intensity of light absorption in the generation range of practically important neodymium lasers. The electronic structure and types of electronic transitions in HMCs are analyzed by the DFT and TD-DFT methods. The influence of vibronic and intermolecular interactions on τ is considered. The advantages of HMCs for passive mode locking of lasers over known dyes with ultrashort τ are demonstrated. The advantages of HMCs to implement passive mode locking of lasers over known dyes with ultrashort τ are demonstrated.
  PubDate: 2023-05-19
  DOI: 10.1007/s11237-023-09760-x