Multicomponent Compounds Research Articles

Tailored engineering of intracrystalline mesopores for boosting multicomponent volatile organic compounds simultaneous deep oxidation

Tailored engineering of intracrystalline mesopores for boosting multicomponent volatile organic compounds simultaneous deep oxidation

A novel approach to the synthesis of superionic LaF3-based multicomponent nanofluorides via trifluoroacetate precursor decomposition

In this study, an approach for the facile and versatile synthesis of multicomponent superionic nanofluorides is proposed. The results of synthesis optimization of the tysonite-type LaF3 and La0.95Sr0.05F2.95 (sp. gr. P3‾c1) nanopowders with a particle size up to 100 nm by the trifluoroacetate precursors thermal decomposition under various conditions (dynamic vacuum and ambient atmosphere) are presented. The produced samples are characterized by X-ray diffraction, electron microscopy, and differential scanning calorimetry. Decarbonization annealing of the initial nanopowders in air at 773 K is urgent for the effective elimination of amorphous carbon formed as a result of the metal-organic precursors decomposition. The nanoceramics were pressed to a theoretical density of 75–80 % and their ion-conducting properties were measured using impedance spectroscopy. The conductivity of decarbonized La0.95Sr0.05F2.95 composition, obtained in a dynamic vacuum, is 1 × 10−3 S/cm at 500 K, which exceeds the performance of undoped LaF3 ceramics by approximately 60 times. The conductive properties of nanoceramics, produced from decarbonized vacuum-synthesized powders, are 5 times higher (1 × 10−3 Sm/cm) compared to mechanochemically fabricated ones. Air-synthesized (773 K) La0.95Sr0.05F2.95 ceramics are conducted significantly worse, although no traces of pyrohydrolysis were detected. Thus, the precursors thermal decomposition method opens up great prospects for the advanced production of ion-conducting nanomaterials based on multicomponent fluoride compounds for solid electrolyte design.

Multi-objective global optimization approach predicted quasi-layered ternary TiOS crystals with promising photocatalytic properties

Abstract Titanium dioxide (TiO2) has attracted considerable research attentions for its promising applications in solar cells and photocatalytic devices. However, the intrinsic challenge lies in the relatively low energy conversion efficiency of TiO2, primarily attributed to the substantial band gaps (exceeding 3.0 eV) associated with its rutile and anatase phases. Leveraging multi-objective global optimization, we have identified two quasi-layered ternary Ti–O–S crystals, composed of titanium, oxygen, and sulfur. The calculations of formation energy, phonon dispersions, and thermal stability confirm the chemical, dynamical and thermal stability of these newly discovered phases. Employing the state-of-art hybrid density functional approach and many-body perturbation theory (quasiparticle GW approach and Bethe–Salpeter equation), we calculate the optical properties of both the TiOS phases. Significantly, both phases show favorable photocatalytic characteristics, featuring band gaps suitable for visible optical absorption and appropriate band alignments with water for effective charge carrier separation. Therefore, ternary compound TiOS holds the potential for achieving high-efficiency photochemical conversion, showing our multi-objective global optimization provides a new approach for novel environmental and energy materials design with multicomponent compounds.

Recognition of multi-component compounds based on occurrence time of secondary crest in the fluorescence lifetime attenuation curve

Fluorescence lifetime is the main characteristic parameter of fluorescence. It is a widely used to draw fluorescence lifetime attenuation curves and to fit fluorescence lifetime parameters by using gated detection methods to identify the species of substances. However, the fluorescence attenuation of each fluorophore in a multi-component compound interferes with one another, affecting the accuracy of identification. In this paper, we propose a method to accurately identify substances by using the occurrence time of the secondary crest of the fluorescence lifetime attenuation curve based on the principle of gated detection to measure the fluorescence lifetime. Furthermore, we design a fluorescence lifetime imaging measurement system and select the same areas of interest in the images for analysis and comparison. The average lifetime of the fluorescence and the occurrence time of the secondary crest are considered as the characteristic parameters. We use five commercially available motor engine oils as the experimental samples and compare the recognition performance of different kernel functions based on a support vector machine (SVM). The radial basis kernel function presents the best performance in terms of recognition accuracy and speed. The recognition rates of the SVM model with the average fluorescence lifetime and the occurrence time of the secondary crest in the attenuation curve of the fluorescence lifetime as a feature vector are 76.24% and 74.65%, respectively. The recognition rate of the SVM model which combines them as feature vectors reaches 91.88%. The experimental results demonstrate that the occurrence time of the secondary crest in the attenuation curve of the fluorescence lifetime can be employed as the basis for substance identification in the analysis of the fluorescence characteristics of multi-component compounds, whose recognition accuracy is similar to the average fluorescence lifetime parameter. Moreover, the occurrence time of the secondary crest of the fluorescence lifetime attenuation curve can be implemented to identify multi-component compounds when it is used as a characteristic parameter.

‘Charge Reverse’ Halogen Bonding Contacts in Metal-Organic Multi-Component Compounds: Antiproliferative Evaluation and Theoretical Studies

Two new metal–organic multi-component compounds of Ni(II) and Co(II), viz. [Ni(3-CNpy)2(H2O)4]ADS·2.75H2O (1) and [Co(3-CNpy)2(H2O)4](4-ClbzSO3)2 (2) (3-CNpy = 3-cyanopyridine, ADS = anthraquinone-1,5-disulfonate, 4-ClbzSO3 = 4-chlorobenzenesulfonate), were synthesized and characterized using single crystal XRD, TGA, spectroscopic (IR, electronic) and elemental analyses. Both the compounds crystallize as multi-component compounds of Ni(II) and Co(II), with uncoordinated ADS and 4-ClbzSO3 moieties in the crystal lattice, respectively. Crystal structure analyses revealed the presence of antiparallel nitrile···nitrile and π-stacked assemblies involving alternate coordinated 3-CNpy and uncoordinated ADS and 4-ClbzSO3 moieties. Moreover, unconventional charge reverse Cl∙∙∙N halogen bonding contacts observed in compound 2 provide additional reinforcement to the crystal structure. Theoretical calculations confirm that the H-bonding interactions, along with anion–π(arene) and anion–π(CN) in 1 and π–π, antiparallel CN···CN and charge reverse Cl···N halogen bonds in 2, play crucial roles in the solid state stability of the compounds. In vitro anticancer activities observed through the trypan blue cell cytotoxicity assay reveal that the compounds induce significant concentration dependent cytotoxicity in Dalton’s lymphoma (DL) cancer cells, with nominal effects in normal healthy cells. Molecular docking studies reveal that the compounds can effectively bind with the active sites of anti-apoptotic proteins, which are actively involved in cancer progression.

Synthesis and Thermal Decomposition of High-Entropy Layered Rare Earth Hydroxychlorides.

The synthesis of multicomponent and high-entropy compounds has become a rapidly developing field in advanced inorganic chemistry, making it possible to combine the properties of multiple elements in a single phase. This paper reports on the synthesis of a series of novel high-entropy layered rare earth hydroxychlorides, namely, (Sm,Eu,Gd,Y,Er)2(OH)5Cl, (Eu,Gd,Tb,Y,Er)2(OH)5Cl, (Eu,Gd,Dy,Y,Er)2(OH)5Cl, and (Eu,Gd,Y,Er,Yb)2(OH)5Cl, using a homogeneous hydrolysis technique under hydrothermal conditions. Elemental mapping proved the even distribution of rare earth elements, while luminescence spectroscopy confirmed efficient energy transfer between europium and other rare earth cations, thus providing additional evidence of the homogeneous distribution of rare earth elements within the crystal lattice. The average rare earth cation radii correlated linearly with the unit cell parameters (0.868 < R2 < 0.982) of the high-entropy layered rare earth hydroxychlorides. The thermal stability of the high-entropy layered rare earth hydroxychlorides was similar to that of individual hydroxychlorides and their binary solid solutions.

Synchronous removal of gaseous toluene and benzene and degradation process shifts in microbial fuel cell-biotrickling filter system

Illustrating the biodegradation processes of multi-component volatile organic compounds (VOCs) will expedite the implication of biotechnology in purifying industrial exhaust. Here, performance shifts of microbial fuel cell and biotrickling filter combined system (MFC-BTF) are investigated for removing single and dual components of toluene and benzene. Synchronous removal of toluene (95 %) and benzene (97 %) are achieved by MFC-BTF accompanied with the output current of 0.41 mA. Elevated content of extracellular polymeric substance facilitates the mass transfer of benzene with the presence of toluene. Strains of Bacteroidota, Proteobacteria and Chloroflexi contribute to the removal of dual components VOCs. Empty bed reaction time and the VOCs concentration are the important factors influencing their dissolution in the system. The biodegradation of toluene and benzene proceeds with 2-hydroxymuconic semialdehyde and o-hydroxybenzoic acid as the main intermediates. These results provide a comprehensive understanding of multi-component VOCs removal by MFC-BTF and guide the system design, optimization, and scale-up.

Supramolecular assembly in Cu(II) and Zn(II) compounds with pyridine and anthraquinone-1,5-disulfonate: Experimental and theoretical analysis

Two new multi-component coordination compounds of Cu(II) and Zn(II) viz. [Cu(py)2(H2O)4]ADS·2H2O (1) and [Zn(4-CNpy)2(H2O)4]ADS·2H2O (2) (py = pyridine, 4-CNpy = 4-cyanopyridine, ADS = anthraquinone-1,5-disulfonate) have been synthesized in aqueous media at room temperature and characterized using elemental and spectroscopic analyses (FT-IR, electronic), TGA and single crystal X-ray diffraction techniques. Both the compounds crystallize as metal–organic multi-component compounds containing complex cationic moieties along with uncoordinated anionic ADS moieties in the crystal structures. Crystal structure analysis of 1 reveals the stabilisation of the layered assembly of the compound assisted by CH⋯O, OH⋯O hydrogen bonding and π-stacking interactions. Antiparallel CN⋯CN and aromatic π-stacking interactions provide rigidity to the crystal structure of compound 2. In addition, enclathration of lattice water molecules within the supramolecular cavity of 2 provides additional reinforcement to the crystal structure. We have carried out theoretical investigations to analyze π-stacking, H-bonding and antiparallel CN···CN non-covalent interactions observed in the compounds using DFT calculations, quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) plot index computational tools. The binding energies of the supramolecular assemblies are quite significant due to the ion-pair nature of the interactions which lack directionality; however, the aforementioned weaker non-covalent interactions play crucial roles in the final arrangement of molecules in the solid state due to their directional nature.

Rational Design of Tetrahedral Derivatives as Efficient Light-Emitting Materials Based on "Super Atom" Perspective.

Traditional semiconductor quantum dots of groups II-VI are key ingredients of next-generation display technology. Yet, the majority of them contain toxic heavy-metal elements, thus calling for alternative light-emitting materials. Herein, we have explored three novel categories of multicomponent compounds, namely, tetragonal II-III2-VI4 porous ternary compounds, cubic I2-II3-VI4 ternary compounds, and cubic I-II-III3-V4 quaternary compounds. This is achieved by judicious introduction of a "super atom" perspective and concurrently varying the solid-state lattice packing of involved super atoms or the population of surrounding counter cations. Based on first-principles calculations of 392 candidate materials with designed crystal structures, 53 highly stable materials have been screened. Strikingly, 34 of them are direct-bandgap semiconductors with emitting wavelengths covering the near-infrared and visible-light regions. This work provides a comprehensive database of highly efficient light-emitting materials, which may be of interest for a broad field of optoelectronic applications.

Estimation of the Lattice Parameter and Lattice Distortion Based on the Results of &lt;i&gt;Ab Initio&lt;/i&gt; Study of Structural Fragments of TiVZrNbMo, TiVZrNbHf, and TiVZrNbTa Multicomponent Alloys

Isolated clusters, fragments of the bcc structure of the compounds of the TiVZrNbMo, TiVZrNbHf and TiVZrNbTa systems, have been constructed and studied from the first principles. An approach has been developed and applied to predicting the lattice parameter and its distortion in solid-state structures based on the results of an Ab initio study of fragments of their structure. It has been established that the predicted values of the lattice constant of the equiatomic compounds TiVZrNbMo, TiVZrNbTa, TiVZrNbHf agree with the available experimental values with high reliability. The developed approach, together with the constructed models of isolated clusters, can be recommended for predicting the lattice parameter and its distortion in new predictive multicomponent metalic compounds.

Metal–organic frameworks for petroleum-based platform compound separations

Metal–organic frameworks for the separation of multicomponent petroleum-based platform compounds based on AST (adsorptive separation technology).

Magnetocaloric, magnetostrictive and 57Fe Mössbauer studies of the multicomponent (Er,Y,Sm)Fe[formula omitted] compounds

The effect of substitutional 4f-elements on the magnetism of rare-earth compounds RFe2-type with the Laves phase structure is studied to find new multifunctional materials, as well as to define the macro- and microscopic parameters of multicomponent magnets. The crystal structure of (Er,Y,Sm)Fe2 compounds is investigated by X-ray powder diffraction. Detailed information on the magnetic properties of the iron sublattice for multicomponent compounds with three different rare-earth elements is obtained for the first time by means of the 57Fe Mössbauer spectroscopy. The main regularities in the magnitude variation of magnetocaloric effect and magnetostriction (linear, anisotropic and volume) in varying composition of the (Er,Y,Sm)Fe2 compounds are determined.

The use of aromatherapy in pediatric practice

Aromatherapy is a method of treatment using natural essential oils injected into the body through the respiratory tract, skin and (or) mucous membranes. Currently, about 3,000 essential oil plants have been studied, from which over 500 organic compounds have been isolated and identified, the number of which in the composition of one essential oil can vary from 120 to 500, and no essential oil has yet been fully investigated.&#x0D; Essential oils are multicomponent organic compounds of terpenes, alcohols, aldehydes, ketones and other hydrocarbons produced by essential oil plants. Biologically active substances of essential oils have a low molecular weight and therefore easily penetrate the skin through the bloodstream. The effect exerted on a person by essential oils is determined in two ways ― neuro-reflex and humoral. Each essential oil is multifunctional. The composition of essential oils can include up to 300 components, so they can have several medicinal properties at the same time, but there is a general trend in the action of essential oils. All of them have immunomodulatory, pronounced bactericidal and antiseptic effects, antiviral and anti-inflammatory properties.&#x0D; In medical practice, the method of hardware aromatherapy is used, the active factor of which is a therapeutic respiratory environment that simulates the natural air background over plants. The study of the effect of essential oils in children's institutions showed their positive effect on the general condition of children, emotional tone, immunological reactivity and nonspecific protection factors, the frequency and severity of respiratory pathology, the course of the adaptation period. The beneficial effect of the complex effect of aromatherapy in the sensory room is shown.&#x0D; Thus, the high efficiency of hardware aromatherapy, good tolerability, the availability of domestic equipment allows us to recommend the method for wide use in therapeutic and preventive and sanatorium-resort institutions.

Evaluation of ambipolar diffusion coefficient in AlxGa1−xN semiconductor

Numerical approach to account for the influence of randomly fluctuating potential on carrier mobility in compound semiconductors with compositional disorder is developed and exploited for calculating the heavy hole-defined ambipolar diffusion coefficient in AlxGa1-xN layers. The rates of inelastic heavy hole-phonon scattering were obtained by integrating the quasi-classical hole-phonon scattering rates for the virtual crystal over the semiclassical confining potential obtained by using the local landscape method. The calculated dependence of the heavy-hole diffusion coefficient on the aluminum content in AlxGa1-xN crystal in a wide compositional range (x = 0 – 1) evidences a substantial influence of localization on the diffusivity of nonequilibrium carriers and is in a good quantitative correspondence with the experimental data obtained in this work by using the light-induced transient grating technique. The adopted Monte Carlo simulation technique also enables diffusivity calculations in other multicomponent compounds (e.g., high-In-content InGaN) and their structures, in particular, those for LEDs and µ-LEDs.

Multi-component volatile organic compounds (VOCs) treatment nexus: High-performance of activated carbon derived from residual agroforestry biomass

Multi-component volatile organic compounds (VOCs) treatment nexus: High-performance of activated carbon derived from residual agroforestry biomass

Microstructure and Wear Resistance of High-Chromium Cast Iron with Multicomponent Carbide Coating via Laser Cladding

High-chromium cast iron (HCCI) coatings with multicomponent carbides were prepared on low-alloy steel substrates using a laser cladding technique in this work. The microstructure and wear resistance of the coatings were characterized via optical microscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and block-on-ring wear testing. Multicomponent carbides (Ti, Nb, Mo, W, V)C with an FCC structure and multicomponent compounds (Nb, Mo, W, V) (B,C) with an FCC structure were found in the microstructures of coatings after multielement doping. In addition, (Cr, Mo, W, V)23C6 compounds could be obtained by heat treatment. These multicomponent compounds were beneficial for obtaining coatings with an excellent hardness (60 HRC) and high wear resistance. This multielement doping method provides an effective modified method for preparing high-wear-resistance laser cladding coatings.

Salts of S-(+)-Ibuprofen Formed via Its Reaction with the Antifibrinolytic Agents Aminocaproic Acid and Tranexamic Acid: Synthesis and Characterization

The paucity of multi-component compounds containing the non-steroidal anti-inflammatory drug (NSAID) S-(+)-ibuprofen (S-IBU) in combination with other drugs prompted the present study, which describes 1:1 salts of this active pharmaceutical ingredient (API) with the two most widely used antifibrinolytic APIs, namely 6-aminohexanoic acid (aminocaproic acid, ACA) and tranexamic acid (TXA), which are zwitterions in the solid state. Since NSAIDs are known to cause adverse side effects such as gastrointestinal ulceration, the presence of ACA and TXA in the salts with S-(+)-ibuprofen might counter these effects via their ability to prevent excessive bleeding. The salts were prepared by both the liquid-assisted grinding method and co-precipitation and were characterized by X-ray powder diffraction and single-crystal X-ray diffraction, thermal analysis, Fourier transform infrared spectroscopy, and solubility measurements. The X-ray analyses revealed a high degree of isostructurality, both at the level of their respective asymmetric units and in their extended crystal structures, with charge-assisted hydrogen bonds of the type N-H+⋅⋅⋅O− and O-H+⋅⋅⋅O− featuring prominently. The thermal analysis indicated that both salts had significantly higher thermal stability than S-(+)-ibuprofen. Solubility measurements in a simulated biological medium showed insignificant changes in the solubility of S-(+)-ibuprofen when tested in the form of the salts (S-IBU)−(ACA)+ and (S-IBU)−(TXA)+.

Syntheses of tetraphosphate cavitands and their supramolecular entities with sodium and copper salts

Modification of the resorcin[4]arenes 1a/1b and the methylresorcin[4]arene 1c by phosphorylation, oxidation, hydrolysis and acidification led to isolation of three new tetraphosphate cavitands 3a–3c. Interactions of the tetraphosphate cavitands 3a–3c with CuCl or CuBr in pyridine afforded three multi-component compounds (3a–H)·[CuCl(py)4]·8H2O (A, py = pyridine) and (3b–3H)·[CuX(py)4]·[Cu(py)3(H2O)3]·nH2O (B, X = Cl, n = 5.6; C, X = Br, n = 5). The molecular structures of 3c·29.2H2O, {3cNa}Cl·7.2H2O, A, B and C have been determined by X-ray diffraction studies. The coordinative and H-bonding interactions of sodium and copper salts with the phosphate groups were presented in {3cNa}Cl·7.2H2O and B/C, respectively, making them dimensional supramolecular entities.

Tandem supported Pt and ZSM-5 catalyst with separated catalytic functions for promoting multicomponent VOCs oxidation

The painting and electronics industries simultaneously release aromatic compounds and chlorinated organics. The development of catalysts with synergistic control of these pollutants is of great significance to achieve air purification. However, developing active catalysts while maintaining good chlorine resistance remain a huge challenge due to the difficulty of the trade-off between the redox properties and acidity and the production of polychlorinated byproducts. Herein, we introduce a novel tandem PtSn/CeO2&Mn/ZSM-5 catalyst and investigate its catalytic performance for multicomponent volatile organic compounds (VOCs) oxidation. The two individual catalysts, PtSn/CeO2 and Mn/ZSM-5, were used to catalyze two distinct sequential reactions. PtSn/CeO2 catalyzed toluene oxidation to produce CO2 and H2O. Meanwhile, the introduction of SnOx favored the adsorption of trichloroethylene (TCE) molecules that prevented Pt sites from chlorine poisoning and possibly converted adsorbed TCE into intermediates, which were subsequently oxidized deeply by the nearby Mn/ZSM-5. This approach resulted in a remarkable oxidation efficiency for toluene (T90 = 296 °C) and TCE (T90 = 384 °C), with fewer unexpected toxic byproducts (chlorobenzene and 4-chlorotoluene). Furthermore, the tandem catalyst possessed excellent chlorine and water resistances. In conclusion, the above findings provide new insights into the design and/or syntheses of advanced catalysts for widespread VOCs pollution control.

Orbital Engineering in Sillén-Aurivillius Phase Bismuth Oxyiodide Photocatalysts through Interlayer Interactions.

Multicomponent inorganic compounds containing post-transition-metal cations such as Sn, Pb, and Bi are a promising class of photocatalysts, but their structure-property relationships remain difficult to decipher. Here, we report three novel bismuth-based layered oxyiodides, the Sillén-Aurivillius phase Bi4NbO8I, Bi5BaTi3O14I, and Bi6NbWO14I. We show that the interlayer Bi-Bi interaction is a key to controlling the electronic structure. The replacement of the halide layer from Cl to I negatively shifts not only the valence band but also the conduction band, thus providing lower electron affinity without sacrificing photoabsorption. The suppressed interlayer chemical interaction between the 6p orbitals of the Bi lone-pair cations reduces the conduction bandwidth. These oxyiodides have narrower band gaps and show much higher water oxidation activities under visible light than their chloride counterparts. The design strategy has not only provided three novel Bi-based photocatalysts for water splitting but also offers a pathway to control the optoelectronic properties of a wider class of lone-pair (ns2np0) semiconductors.