Structural Formula Research Articles

Study on the Simplified Chemical Kinetic Combustion Mechanism of Mixed Methanol/PODE Fuel for Marine Diesel Engines

As a clean alternative fuel oil for marine engines, methanol has received increasing attention, but its low cetane number requires diesel ignition, which increases the difficulty of retrofitting existing engine fuel injection systems. Polymethoxy dimethyl ether (PODEn) is an ether fuel mixture whose chemical structural formula can be expressed as CH3O(CH2O)nCH3 (n≥2). PODE3 is the predominant component in the blend, and its properties are representative of the blend. PODE is a low-carbon fuel with a high cetane number and is easy to compression ignite, and, as such, can be used to ignite methanol in a marine diesel engine. This article explores the combustion mechanism of mixed methanol–PODE fuel using the characteristics of PODE that can be easily mixed with methanol for combustion. Taking methanol and PODE3 as representative fuels, the detailed combustion mechanism of PODE3 and the detailed combustion mechanism of methanol are simplified using a DRGEPSA (direct relationship graph with error propagation (DRGEP) and sensitivity analysis (SA)) method. Based on the target engine cylinder combustion environment, a simplified mechanism for mixed methanol–PODE fuel is obtained, and the new mechanism is validated in terms of the ignition delay period and laminar flame speed. The results indicate that the newly constructed simplified mechanism is basically consistent with the ignition delay data and flame propagation speed data measured by a rapid compression machine (RCM), laying the foundation for the application of alternative methanol fuels in marine engines.

On-site rapid detection of perfluorooctanoic acid by visual immunochromatographic strip biosensor in domestic water and real human samples

The International Agency for Research on Cancer (IARC) classifies PFOA as a Class 1 carcinogen. Here, a new naked-eye PFOA immunochromographic strip was developed to recognize PFOA in domestic water and real human samples within 10 min based on a novel custom designed anti-PFOA monoclonal antibody (mAb) 2A3, which was firstly an immune rapid detection method for PFOA has been proposed. Using computer simulation techniques such as quantum computing to assist in designing the structural formula of PFOA semi antigen, which hapten was firstly proposed. The half maximal inhibitory concentration of PFOA monoclonal antibody (mAb) 2A3 was 2.4 μg/mL. Using mAb 2A3, we developed an immunochromatographic strip (ICS) for detecting PFOA in real samples. The developed method generated results in 10 min, with visual detection limits of 20, 20, and 200 μg/mL and limit of detection of 50, 200, and 500 μg/mL for water, blood and urine samples, respectively. The established ICS and indirect competitive enzyme-linked immunosorbent assay were used to analyze the actual samples, and the results were confirmed by LC-MS/MS. Our study findings showed that the ICS and ic-ELISA can quickly detect PFOA in actual samples.

The Neocolonial Structural Model Re-Foundation and The Pragmatic Inference of Organizational Culture in Ngugi Wa Thiongo’s Devil on The Cross (1980)

Through the frame frequency of the imported state and the westernization of the African political order, the social construction of the African bureaucracy appears as a structural device of abstraction, exploitation, and brutality. Then, through the frame of reference with the importation of conceptual juridical coordination and perceptual representative consensus, the African public administration enhances a frameshift transformation and a succession of causality. Therefore, in combinatorial and transactional analysis, the framework of Devil On The Cross progresses in a method of empirical processing decomposition. Within this respect, the elemental and pure imaginary of the African administration proceeds as a functional derivative governmentality and a colonial functional inception power. Subsequently, with its interaction design, processing system, and volume technique, the realm of Devil On The Cross inserts a paradigmatic analysis and a value engineering within which this African administration happens as an characteristic structural formula and an inefficient relational frame theory. Moreover, within the space-time continuum, the configuration management and the linear configuration programming of the African management apparatus, Devil On The Cross becomes a holomorphic function and an analytic continuation that reveal the anachronism nature and the asynchronous system of the African post-colonial administration.

Search for molecular descriptors and computer prediction of biological activity in a series of S-derivatives (1,2,4-triazole-3(2H)-yl)methyl)thiopyrimidines

Most pharmaceutical compounds interact with various molecular compositions in the body, leading to complex biological effects. Furthermore, during biotransformation, they may generate one or more metabolites with potent bioactive properties. Therefore, the development and careful use of new medications require thorough examination of their biological impact profiles, including considerations of human metabolic processes. In silico techniques are currently widely used to evaluate the interactions of emerging drug candidates with pharmacological conditions and predict their metabolic conversions. To investigate the bioactivity of compounds based on the structure of 1,2,4-triazole-3(2H)-thione with pyrimidine-2-thiol, we generated a combinatorial library of bioregulators using the computer programs SuperPred and SwissADME. The relevance of this research is underscored by the ongoing quest for novel biomolecular compounds that are highly effective yet low in toxicity, spanning both natural and synthetic sources. Much attention is directed towards nitrogen-containing heterocycles, particularly derivatives of 1,2,4-triazole, due to their substantial medical and biological potential. The aim of the work is to create a combinatorial library of bioregulators, which contains the structures of 1,2,4-triazole and pyrimidine, and to carry out in silico screening of heterocycle derivatives using the SuperPred web server to determine promising directions for the study of their bioactivity. Materials and methods. The subject of our research is S-derivatives of (1,2,4-triazole-3(2H)-yl)methyl)thiopyrimidines. Virtual screening of compounds was carried out using the SuperPred computer program. The ADME study was performed using the free service SwissADME, which is used to evaluate the pharmacokinetics, bioavailability, and interaction of small molecules with enzymes in medicinal chemistry. Results. Predicting the likelihood of a substance demonstrating a particular biological activity enables the selection of the most appropriate tests for studying the activity of a given chemical compound, as well as identifying which substances available to the researcher are most likely to enhance the effectiveness of the effects. This principle is grounded in the concept that “the biological activity of a substance is a function of its chemical structure”. Such predictions are generated based on the structural formula of a chemical compound and can be made during the planning stage of synthesis. Conclusions. A combinatorial library of bioregulators was created by combining the structure of 1,2,4-triazole-3(2H)-thione with pyrimidine-2-thiol. The conducted virtual screening of the 1,2,4-triazole-3(2H)-thione heterocycle with pyrimidine-2-thiol shows promise for obtaining non-toxic compounds with antineoplastic biological activity. Screening of derivatives, particularly S-derivatives of (1,2,4-triazole-3(2H)-yl)methyl)thiopyrimidines, indicates the potential for discovering biologically active substances with antineoplastic, antibacterial, analgesic, antidiabetic, antihypertensive, and other types of biological activities within this compound series.

Design of Jacob’s ladder-based teaching aids for illustrating the dualities of benzene derivatives

Abstract The dualities of benzene derivatives often make basic organic chemistry challenging for students. This includes the relationship between full structural and line-angle formulas, the distinctions between preferred and systematic IUPAC names for benzene derivatives, and the nuances between ortho-, para-, and meta-directors. To effectively demonstrate these dualities of benzene derivatives, we have designed a range of teaching aids rooted in the folk toy, Jacob’s ladder. This paper presents lectures designed for advanced placement high school students and nonchemistry majors, employing this innovative series of Jacob’s ladder-based teaching aids. The majority of students found the lecture engaging, and many developed a comprehensive understanding of the dualities of benzene derivatives.

The Conformational Contribution to Molecular Complexity and Its Implications for Information Processing in Living Beings and Chemical Artificial Intelligence.

This work highlights the relevant contribution of conformational stereoisomers to the complexity and functions of any molecular compound. Conformers have the same molecular and structural formulas but different orientations of the atoms in the three-dimensional space. Moving from one conformer to another is possible without breaking covalent bonds. The interconversion is usually feasible through the thermal energy available in ordinary conditions. The behavior of most biopolymers, such as enzymes, antibodies, RNA, and DNA, is understandable if we consider that each exists as an ensemble of conformers. Each conformational collection confers multi-functionality and adaptability to the single biopolymers. The conformational distribution of any biopolymer has the features of a fuzzy set. Hence, every compound that exists as an ensemble of conformers allows the molecular implementation of a fuzzy set. Since proteins, DNA, and RNA work as fuzzy sets, it is fair to say that life's logic is fuzzy. The power of processing fuzzy logic makes living beings capable of swift decisions in environments dominated by uncertainty and vagueness. These performances can be implemented in chemical robots, which are confined molecular assemblies mimicking unicellular organisms: they are supposed to help humans "colonise" the molecular world to defeat diseases in living beings and fight pollution in the environment.

Formulas for Calculating Deformations and Natural Frequency of Free Vibrations of a Hexagonal Tower

Statement of the problem. A scheme of a six-sided prismatic statically determinate spatial girder is proposed. The task is set by induction to derive formulas for the dependence of the deflection of the structure and the lower limit of the main frequency of natural vibrations on the number of panels along the height of the prism. Materials and methods. The forces in the rods along with the reactions of the supports are found in an analytical form by means of the method of cutting nodes in the Maple symbolic mathematics system. One of the nodes at the base of the truss has a spherical support, one has a cylindrical support, the remaining four supports are racks. The top deflection is determined by the Maxwell-Mohr formula. From the analysis of the sequences of coefficients in the formulas for individual structures with a different number of panels, their common members are determined, which are included in the desired calculation formula. The Dunkerley method is used to estimate the first frequency of free oscillations. Results. For various types of loads, formulas for the dependence of girderf deflections on the number of panels are obtained. The coefficients in the solution are polynomial in the number of panels. The derived analytical dependence of the first frequency on the number of panels in comparison with the numerical solution has a small error, which decreases with increasing number of panels. Conclusions. A design of an axisymmetric statically determinate tower-type girder has been developed, which allows analytical solutions to the problem of deflection and the problem of the first natural frequency for an arbitrary number of panels. The resulting formulas can be used to assess the accuracy of numerical solutions and for preliminary calculations of models of structures of this type.

Experimental and Theoretical Study of Seepage Models under Confining Pressure for a Single Rock Fracture

The engineering water inrush events were affected by the hydraulic characteristics of the fractures. In order to quantitatively study the seepage characteristics of the fractures, the experimental analysis of artificial fracture of shale was carried out under different confining pressure (22 MPa – 38 MPa) to explore the influence of confining pressure on seepage characteristics. Three theoretical constitutive formulas to describe the characteristics of seepage were proposed based on cubic law and fracture constitutive equation (Bandis model, Rong model, Sun model), and these theoretical constitutive formulas all had good fitting results to experiment results which indicated that the derived formulas are feasible. The parameters for the three models were compared, among which the Rong model was more suitable to describe the connection between (Q) and (Pc). Rong model and Sun model were highly descriptive to the relationship between (Pc) and (Ps). The formulas that based on three theoretical models can provide quantitative calculation for the influence of in-situ stress change on the seepage of fractures in engineering practice.

Idealization in pharmacology and pharmacy: Symbol of the chemical formula of one molecule of a substance and a real pharmaceutical product

The essence of the two levels of information used in modern pharmacy, pharmacology, and medicine for operations related to theoretical reasoning about medicines and the actual practice of their use for treating specific cases is fundamentally different. In particular, studies have analyzed the essence of theoretical information about medicines and the norms of their use in accordance with medical care standards. Information about medicines and standards of medical care, which dominate textbooks, reference books, encyclopedias, scientific articles , and normative and technical documents, is built on the idealized essence of chemically pure substances and their interaction with an idealized virtual patient. Accordingly, in the fields of pharmacy, pharmacology, and chemistry, physics, and materials science, researchers have traditionally represented chemical elements (and drugs) by certain chemical formulas, names, and symbols for their molecules. Moreover, in pharmacy and pharmacology, the structural formula of one molecule of only one chemical substance belonging to the group of the so-called main active substances most often plays this role. Generally, this chemical symbol of its molecule is identified with the real substance itself. It is assumed that the substance in question is of ideal high quality, is completely free of any impurities, is not combined with other substances, and does not represent a certain pharmaceutical product (it is not a tablet, not a solution, not an ointment, not an aerosol, etc.), and is not manufactured by a certain pharmaceutical company according to a certain recipe. Moreover, modern pharmaceutical products are not separate molecules, not pure chemical reagents, but all sorts of mixtures of different substances of different quality in different ratios. In addition, each pharmaceutical product of each manufacturing plant and each series number has inherent and unique mechanical, physical, chemical, and physicochemical properties and quality indicators. Therefore, the idealized essence of drugs is far from that of real pharmaceutical products. The chemical name and chemical formula are symbols of one molecule of a chemical element, reflecting its idealized chemical essence, but not the essence of a real “tablet”, “ampule”, and/or “tube” with it. In turn, the virtual patient of known sex, average age, average health status, and a body weight of approximately 70 kg implied by the standards of medical care is just an idealized object of interaction with an idealized “medicine”. In this regard, the study of the relationship between the idealized and real drugs and patients is a crucial part of the problem of the relationship between theory and reality in pharmacy, pharmacology, and medicine.

Flexible Phenanthracene Nanotubes for Explosive Detection.

Phenanthracene nanotubes with arylene-ethynylene-butadiynylene rims and phenanthracene walls are synthesized in a modular bottom-up approach. One of the rims carries hexadecyloxy side chains, mediating the affinity to highly oriented pyrolytic graphite. Molecular dynamics simulations show that the nanotubes are much more flexible than their structural formulas suggest: In 12, the phenanthracene units act as hinges that flip the two macrocycles relative to each other to one of two possible sites, as quantum mechanical models suggest and scanning tunneling microscopy investigations prove. Unexpectedly, both theory and experiment show for 13 that the three phenanthracene hinges are deflected from the upright position, accompanied by a deformation of both macrocycles from their idealized sturdy macroporous geometry. This flexibility together with their affinity to carbon-rich substrates allows for an efficient host-guest chemistry at the solid/gas interface opening the potential for applications in single-walled carbon nanotube-based sensing, and the applicability to build new sensors for the detection of 2,4,6-trinitrotoluene via nitroaromatic markers is shown.

Guanine Metal Complexes: Spectroscopic Studies, Dying Performance and as Indicator

Azo dyes are the most common and widely used dyes, accounting for more than half of each year's dyes. In this work, a complete description of a new innovative series of compounds with the elements [Ag (I), Zn (II)] generated from the guanine azo dye ligand (GAB) 8-[1-(3-carboxy) azo] guanine has been studied. The structural formula was studied using several physicochemical analyses and spectroscopic techniques (FT-IR spectra, UV-Vis). The FTIR spectrum of the ligand (GAB) was compared to the spectra of the metal ion complexes formed to determine its identity. Chelating caused some changes in the spectra of the complexes to appear to demonstrate that they could be linked to the ligand. The complexes have a tetrahedral geometry shape, the ligand functions as a bidentate ligand, and thermogravimetric analysis (TGA) is used to measure the thermal stability of compounds. The findings and equation presented by the analytical data seemed to be in good accord with the conclusions of the thermogravimetric investigation, which demonstrated that the disintegration of the ligand (GAB) and its complexes occur in multiple steps. The configuration that follows weakens thermal stability: GAB(35.52%)>[Ag(GAB)(H2O)2]NO3.2H2O(34.6%)>[Zn(GAB)Cl2].H2O(31.54%), and the complexes have tetrahedral geometry shape. Furthermore, elemental analysis, mole ratio, and the mole ratio of each complex (1:1) (M:L). The ligand was effective as an acid-base indicator when the pH changed; they exhibited a striking color change, similar to how the ligand (GAB) and its complexes can be used to dye wool textiles due to their wide range of colors. It investigated how well the ligand (GAB) and its complex worked as a wool dye. The ligand GAB and its metal complexes were used to color most of the protein filaments in wool fiber, which have a complex structure with amino and carboxyl groups and colors ranging from orange to green.

Synthesis, characterization, antimicrobial, molecular docking simulation, and antitumor assays of nanometric complexes based on new thiazole Schiff base derivative

For further pharmaceutical applications, a novel Schiff base derivative of aminothiazole and its Co (II), Cu (II), Zn (II), and Th (IV) chelates were designed and prepared. For this purpose, 2‐aminothiazole and 2,4‐dihydroxybenzaldehyde have been coupled before the complexation reaction with the metal salts. Elemental analysis, FT‐IR, 1HNMR, UV–Vis spectra, transmission electron microscopy (TEM), X‐ray powder diffraction (XRD), molar conductance, and magnetic moment measurements were used to determine the structural formula of the ligand and its produced chelates. The acquired data pointed out that the ligand was chelated with metal through the nitrogen of azo group and deprotonated ortho phenolic oxygen atoms. In Cu (II) complex the copper ion chelated with two ligand molecules, whereas in other complexes the metal binds with one molecule only of ligand. It was shown by XRD patterns and high‐resolution TEM images that the complex particles had a uniform distribution across the chelates' surfaces and were nanometric in size. Extremely, antimicrobial and anticancer activity for the prepared ligand and complexes were investigated, which showed high activity, especially after complex formation. Docking studies have been performed to predict the compounds' efficacy as antitumor agents through their interaction with the co‐crystal structure of proteins for breast cancer cells (PDB ID: 3S7S) and protein of liver cancer 2 (PDB ID: 2JW2). The experimental results of the anticancer activity showed promising results, especially for Cu (II) compound which exhibited the greatest antitumor efficacy (IC50 = 12.81 μg/ml) contra HepG‐2 carcinoma and Mcf‐7 cells (IC50 = 18.92 ± 0.91 μg/ml). Antimicrobial activity against the strains Klebsiella pneumoniae (K. pneumoniae), Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), C. albicans (C. albicans), and Aspergillus niger (A. niger) also gave very promising results when it is compared with the standard drugs.

Connection design method of honeycomb plate-rod composite structure: Experimental study and theoretical analysis

The connection design method of plate-rod composite structure is very important for the cooperative work of plate and rod. In this study, ten kinds of plate-rod composite structures of different connection methods, connection spacings, and plate thicknesses were designed to examine the connection performance of composite structure. The applicable finite element analysis methods of three connection methods were obtained by comparing the calculation results of finite element simplification models. The influence of connection spacing, connector diameter and plate thickness on the connection performance of three connection methods was studied by parametric analysis. The optimized shear bearing capacity formula of three connection methods were proposed based on the connection performance test and the design specifications at home and abroad. The bending bearing capacity formula of composite structure were proposed by theoretical derivation and finite element analysis, and the relevant parameters were fitted by the Backward Propagation (BP) algorithm in neural network. The results shown that the connection performance of Self-Piercing Riveting connection is obviously better than that of one-side bolt and core-pulling rivet connection, and the bearing capacity is increased by about 6 % and 10 %. The connector solid (So-1-1), solid simplified beam (So-3-1 and So-3-2), and shell simplified beam (Q-1) modeling method can better simulate the one-side bolt connection, and the error is within 3 %. The connector solid (So-1-2), solid beam (So-2-1), embedded (So-4-1), and shell simplified beam (Q-1) are suitable for core-pulling rivet connection, and the error is within 5 %. All the finite element analysis simplification methods can accurately simulate the Self-Piercing Riveting connection except for the Q-2, and the error is within 2 %. The bearing capacity of the composite structure increases with the increase of the connector diameter, the decrease of the connection spacing and the increase of the plate thickness. The optimized shear bearing capacity formula are more suitable for practical application, and the error of the bending bearing capacity formula of composite structure is within 5 %, which provides a certain reference for the design of honeycomb plate-rod composite structure and the revision of relevant specifications in the future.

Synthesis, crystal structure, BFDH morphology, Hirshfeld surface analysis and electrical characterization of the new bi-(2-amino-5-methylpyridinium) hexa-chlorostannate compound

The Organic–inorganic hybrid compounds have attracted considerable attention for their scientific and technological potential according to their wide field application. In this paper, we describe the preparation of a new hybrid crystal, with the structural formula [C6H9N2]2SnCl6, of which crystallographic, BFDH morphology, Hirshfeld and complex impedance spectroscopy have been studied and analyzed. The X-ray diffraction analysis revealed that the title compound crystallized in the centrosymmetric space group P21/c of the monoclinic system. The powder XRD is used to confirm the phase purity of the sample and the crystalline nature of the powder.The [C6H9N2]2SnCl6 crystal morphologies are simulated from the Laue symmetry (2/m), and from the space group symmetry (P21/c), which highlighted the effect of the screw axe 21 and the glide plane c in reducing the Importance morphology in the constructed model considering the space group symmetry. The intermolecular interactions studied using Hirshfeld surfaces showed the important contribution of H⋯Cl/Cl⋯H intercontacts (67.1 %) in the [C6H9N2]2SnCl6 crystal packing.The analysis of real and imaginary parts impedance spectra shows that the electrical properties are heavily dependent on frequency and temperature, indicating a relaxation phenomenon and semiconductor-type behavior. The Nyquist plot (-Z″ vs Z′) showed only one semicircular arc, representing the grain effect in the electrical conduction. The obtained results were analyzed by fitting the experimental data to an equivalent circuit model R/CPE/C. The Alternating current conductivity (σAC) follows Jonscher's power law. The latter confirmed that the conduction is insured by the non-overlapping small polaron tunneling model (NSPT) model, which has been studied in depth.

DETERMINATION OF THE UPPER LIMIT OF THE LOAD-LOADING CAPACITY OF BENDING REINFORCED METAL-COMPOSITE RING PLATES IN CONTACT WITH A LIQUID INCOMPRESSIBLE MEDIUM 1. PROBLEM FORMULATION AND CALCULATION METHOD

The problem of determining the load-bearing capacity of a bendable reinforced annular plate resting on an incompressible liquid base is considered. The internal opening of the structure is closed with a continuous, absolutely rigid insert. The connection between the insert and the plate can be rigid or hinged. The structure is supported on the outer edge, and it is possible to move the support in the vertical direction, for example in the case of a movable jamming. In the limiting state, liquid flow from one front surface of the plate to another surface is not allowed. The materials of the components of the composition are isotropic and rigid-plastic, having the same yield limits in tension and compression. Plastic flow in the phases of the composition is associated with piecewise linear yield criteria (such as the Tresk's or Ishlinsky - Ivlev's yield conditions). The limit state of such a composite plate is described within the framework of the classical theory of transverse bending. Reinforcement structures have axial and radial symmetry. Two reinforcement options are considered: laying two families of fibers along radially symmetrical spiral trajectories and reinforcement in the radial and circumferential directions. The rein-forcing fibers are assumed to be continuous and have constant cross sections along their length, which gives rise to significant heterogeneity of the structures under consideration in the radial direction. The plastic flow of a metal-composition is calculated using a structural model that takes into account the presence of a plane stress state in all substructural elements. Structural formulas have been written that make it possible to determine the coordinates of corner points on piecewise linear yield curves of the compositions under consideration, taking into account their dependence on non-uniform reinforcement parameters: angles and densities. An extremal principle has been formulated that makes it possible to obtain an upper (kinematic) estimate of the maximum load for this type of structure. The formulated problem is discretized along the polar radius. Nodal values of the sagging speed and mechanical energy dissipation were used as unknown grid functions. A numerical algorithm for solving the formulated discretized problem has been developed, based on the application of the simplex method of linear programming theory.

Технология производства защитных антикоррозионных материалов из жиросодержащих отходов

The processing of fat-containing waste from meat-packing enterprises that cannot be landfilled is an urgent problem. The authors developed the technology of processing fat-containing waste in a chemical reactor in one step, without dividing the technology into two steps: triglyceride hydrolysis and fatty acid amide production. The technology for processing fat-containing waste was tested in a laboratory plant. The target product obtained was analyzed using IR spectroscopy. As a result, the structural formula was clarified, functional groups were determined, and chemical intermediates in the synthesis process were identified. The proportions of the reagents were determined: technical fat in the amount of 65.3‑72.4 wt%, monoethanolamine - 14.5‑17.0 wt% and boric acid - up to 100 wt% of the mixture. The reaction time was 1.5 h. The protective effect was selected as a quality control indicator of the surfactant obtained. Solvent selection was carried out for producing anticorrosive materials. I‑20 industrial oil, diesel fuel and SN‑150 oil were selected as solvents. Electrochemical studies carried out on the AVTOLAB PGSTAT302N potentiostat-galvanostat made it possible to determine the mechanism of action of the surfactant as a corrosion inhibitor. Its optimum concentration was found to be 15%, with a protective efficiency of 99.33%. To increase the protective anticorrosive efficiency of the surfactant, the tests were carried out in a humidity chamber for 60 days on St3 steel plates. The test results showed high efficiency of the surfactant used as a corrosion inhibitor, with the Z value of more than 90%.

Chromatography of Solanum habrochaites extracts with the first record of the docosanoate, hexadecanoate and octadecanoate ethyls in this plant and in Solanaceae.

The increasing need for sustainable alternatives to synthetic insecticides has driven the analysis of extracts from Solanum habrochaites, a wild tomato, through fractionated column chromatography. Potential bioactive compounds for pest management, a clean and promising biotechnological solution, have been reported from this plant. The objective is to provide detailed gas chromatography data, including peaks, structural formulas, and retention indices for the extracts of S. habrochaites aerial parts. Column chromatographic analysis was conducted with five fractions (F1, F2, F5, F3, and F4) of S. habrochaites extracts. Long-chain hydrocarbons such as hexadecanoic acid and docosano were identified in the F1 fraction; fatty acid esters, including hexadecanoate and octadecenoate ethyls in the F2 and methyl ketones, with tridecan-2-one as the major component in the F5, while no identifiable compounds were disclosed in the F3 and F4 fractions. The column chromatography provided valuable insights into compounds in the F1, F2, and F5 fractions of S. habrochaites extracts, highlighting fatty acid esters, long-chain hydrocarbons, and methyl ketones. The bioactive compounds, from extracts of this plant, including the first record of the docosanoate, hexadecanoate and octadecanoate ethyls in S. habrochaites and Solanaceae, reinforces their promising biological application in different areas of science.

Low thermal conductivity in a new mixed metal telluride Mn1.8(1)In0.8(1)Si2Te6.

The design of new complex mixed metal tellurides (containing low toxicity cations) with intrinsic ultralow thermal conductivity is of paramount importance in the field of thermoelectrics. Herein, we report the synthesis and characterization of polycrystalline and single crystals of a new mixed-metal quaternary telluride Mn1.8(1)In0.8(1)Si2Te6. The structural aspects and chemical formula of this phase at room temperature have been established using single crystal X-ray diffraction and EDX studies. The trigonal centrosymmetric (space group: P3̄1m) structure of the title phase has cell constants of a = b = 7.0483(7) Å and c = 7.1277(8) Å. The structure has three independent cationic sites, one mixed (In1/Mn1), one partially filled Mn2, and one Si1, which are bonded with Te1 atoms. Each metal atom (In and Mn) in the structure is octahedrally coordinated with six neighboring Te1 atoms. The structure also features dimers of Si atoms, and each Si atom is bonded to three Te1 atoms to form ethane-like Si2Te6 units. The optical absorption study of a polycrystalline Mn1.8In0.8Si2Te6 sample shows a narrow optical bandgap of 0.6(2) eV. Temperature-dependent resistivity and Seebeck coefficient studies confirmed the p-type semiconducting nature of the sample with high values of S (301 μV K-1 to 444 μV K-1). The total thermal conductivity (ktot) study of the polycrystalline sample shows a decreasing trend on heating with an extremely low value of 0.28 W m-1 K-1 at 773 K. Magnetic measurements indicate a glassy magnetic behavior for the sample below 8 K.

Spectroscopic and thermal studies of mixed ligand coordination compounds of cobalt (II) with aspartic and dicarboxylic acids

The synthesis of complex compounds of cobalt (II) ion in the presence of aspartic and dicarboxylic acids has been studied by thermal and spectroscopic methods. Thermal decomposition processes of these compounds are studied on the basis of thermal analysis, and endo- and exoeffects are determined. The decomposition products of the compounds were studied on the basis of mass reduction by the thermogravimetric method. Based on the results of spectroscopic studies, the structural formulas of the synthesized coordination compounds are established.

Хімічні властивості та характеристики поверхневої активності гумінової кислоти з бурого вугілля

The article is devoted to the study of some specific physicochemical properties of humic acids, which are attracting increasing attention due to their potential applications. The unique structural composition, which includes both hydrophilic and hydrophobic sites, makes these materials a versatile agent in various technological processes. It has been shown that humic acid solutions have the properties of surfactants and can serve as a natural alternative to surfactants. The paper presents the results of studies of a sample of humic acid obtained from lignite. Infrared spectroscopy has revealed signs of the aromatic structure of humic acid, the presence of phenolic and other functional groups, such as hydroxyl and nitrile. The presence of carboxylic acids, esters, and complex esters was established. The complex and heterogeneous nature of humic acids has been confirmed, which makes them promising for use as surfactants. No clear evidence of the presence of -NH₂ groups was found in the IR spectrum. This suggests that lignite humic acids generally correspond to the structural formula reported in the literature. The potentiometric titration of the lignite humic acid sample made it possible to determine the dissociation constants of functional groups. The obtained values are close to the calculated dissociation constants of carboxyl groups for the model molecule of lignite humic acid. The analysis of the calculated properties of humic acid based on various structural models showed that lignite is a promising raw material for the production of humic acids with certain surface-active properties. Compared to other structures, humic acid from lignite is more hydrophobic and less soluble in water, which indicates the prospects of its use as a surfactant with better interaction with the oil phase. Keywords: humic acids, lignite, surfactant, infrared spectroscopy, composition, functional groupsб structural model. Corresponding author: Bannikov L.P., e-mail: ukhinbannikov@gmail.com