X-ray Diffraction Methods Research Articles

Исследование продуктов синтеза в механоактивированных смесях титанидов меди с углеродом

Metal matrix composites reinforced with dispersed carbide particles have an optimal combination of strength and wear resistance. The composites are used as structural materials, wear-resistant materials and coatings as well as functional materials. Copper matrix composites for electrical purposes are strengthened with particles of refractory compounds (carbides, borides, silicides). They are used to manufacture breaking electrical contacts which have increased resistance to erosion under the electric arc exposure. The highest arc erosion resistance is achieved by composites with a structure, in which submicron particles of refractory compounds are homogeneously distributed in the copper matrix. Powder technologies are used to obtain the copper matrix composites. A large number of publications concerns with the production of copper matrix composites strengthened by dispersed particles of titanium diboride. The composite powder was obtained by self-propagating high- temperature synthesis (SHS) occurring through mechanically activated mixtures of titanium, copper and carbon. The synthesis products were compacted by spark plasma sintering (SPS). In the present work, the microstructure, elemental and phase composition of the products of the synthesis reaction occurring through mechanically activated reactant powder mixtures of copper titanides with carbon (soot) subjected to additional heat treatment were studied using the methods of X-ray diffraction, optical and scanning electron microscopy. Copper matrix composites strengthened by carbide particles were obtained by copper reduction from intermetallic compounds (copper titanides) via reaction: TimCun+ C → TiC + Cu. The use of the copper titanides instead of titanium and copper powders eliminates the blocking of surface titanium-carbon reaction by copper during the mechanical activation of titanium-copper-carbon powder mixtures. This ensures a more complete conversion of titanium carbide in the synthesis reaction. It is established that the dispersion of the carbide phase in the structure of the synthesized ‘titanium carbide-copper binder’ composite depends on the elemental ratio of titanium and copper in the reaction mixtures. With an equiatomic content of titanium and copper the synthesis results in a matrix-type composite, in the structure of which submicron (less than 300 nm) carbide inclusions are homogeneously distributed throughout the copper binder. Unreacted copper and titanium in the titanide powders do not prevent the attainment of target phase composition of the synthesis products that include only titanium carbide and copper.

Водородные и галогенные связи в трииодаминобензоатах азотистых оснований

The crystalline structures of three organic salts of triiodoaminobenzoic acid (1–3) and triiodoaminobenzoic acid monohydrate (4) are described, the structural features are established by the X-ray diffraction method. Compound 1: C20H19I6N3O6, М 1158.78; monoclinic syngony, space group Сс; cell parameters: a = 32.0782(10), b = 9.5284(3), c = 9.3745(3) Å;  = 90, β = 90,0(1),  = 90 deg.; V = 2865.35(16) Å3, Z = 4, ρcalc. = 2.684 g/cm3. Compound 2: C16H15I6N3O4, М 1074.71; monoclinic syngony, space group P21/c; cell parameters: a = 8.990(5), b = 28.541(11), c = 9.945(5) Å;  =  = 90, β = 91.23(2) deg.; V = 2551(2) Å3, Z = 4, ρcalc. = 2.798 g/cm3. Compound 3: C17H17I3N2O4, М 694.03; monoclinic syngony, space group I2/a; cell parameters: a = 36.02(2), b = 7.254(5), c = 16.468(9) Å;  =  = 90, β = 105.29(2) deg.; V = 4150(4) Å3, Z = 8, ρcalc. = 2.222 g/cm3. Compound 4: C7H6I3NO3, М 532.83; rhombic syngony, space group Iba2; cell parameters: a = 30.2146(4), b = 13.9830(2), c = 5.80740(10) Å;  = β =  = 90 deg.; V = 2453.57(6) Å3, Z = 8, ρcalc. = 2,885 g/cm3. The crystalline structure of two salts and triiodoaminobenzoic acid monohydrate is distinguished both by domination of hydrogen bonds and multiple halogen bonds. However, the 7-methylquinoline salt is devoid of halogen bonds due to peculiarities of the stack packaging of flat molecules. For two compounds (3 and 4), the features of their thermolysis by thermal analysis (in argon atmosphere) are determined: at the first stage (52 and 73 °C, respectively), the loss of crystallization water occurs; at 700 ° C under the thermolysis conditions of both compounds the decomposition product is glass carbon.

Experimental Studies of Schiff Base (E)-4-methoxy-2-(((2-phenoxyphenyl)imino)methyl) phenol Compound with Various Spectroscopic Methods

Schiff-based compounds, which represent an important class in the field of organic compounds, form the basis of this research article. This research article aims to investigate the synthesized compound (E)-4-methoxy-2-(((2-phenoxyphenyl) imino) methyl) phenol using experimental methods.FT-IR, UV-Vis, 13C and 1H Nuclear Magnetic Resonance (NMR) Spectroscopy and X-ray diffraction methods were used to elucidate the structural properties of the compound synthesized at the end of chemical processes. The structure solution was carried out from the data obtained as a result of X-ray analysis. According to these results, one of the two compounds in the asymmetric cell completed their formation in the enol-imine form and the other in the keto-amine form. This structural situation, which is rare in the literature, was supported and explained by FT-IR, 13C and 1H Nuclear Magnetic Resonance (NMR) spectroscopy studies.According to the results obtained as a result of UV-Vis spectroscopy, the structure revealed that the enol-imine form was dominant. The reasons for this situation were explained.

Solid polymer electrolyte and antimicrobial performance of Polyvinyl alcohol/Silver nanoparticles composite film

A nanocomposite based on polyvinyl alcohol (PVA) is developed using silver nanoparticles (Ag NPs) prepared by the chemical reduction method. The nanocomposite is analyzed by X-ray diffraction method (XRD) and Fourier transform infrared (FTIR) analyses. XRD analysis confirms the purity of the synthesized silver nanoparticles with the average crystallite size of 15 nm. It also shows the presence of nanoparticles in the nanocomposite films. The interaction of silver nanoparticles with the polymer matrix is demonstrated by the FTIR spectrum. Scanning electron microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDAX) and UV–Visible spectroscopy confirm the formation of silver nanoparticles with spherical morphology and surface Plasmon resonance at 424 nm. Further, nanocomposite as solid polymer electrolyte and antimicrobial properties of the nanocomposite are illustrated. The addition of nanoparticles increases the electrical conductivity (1.7866 × 10-6 Scm−1) of the PVA silver nanocomposite film that is measured from electrochemical impedance spectroscopy through Cole-Cole plots. The PVA/Silver nanoparticles composite films show a high zone of inhibition for both Gram-negative and Gram-positive bacteria than pure PVA films. The electrochemical performance shows the ability to use as a solid polymer electrolyte in electrochemical devices. Polyvinyl alcohol (PVA)/Silver nanoparticles composite films with high anti-bacterial activity can be used for wound dressings and active food packaging.

Evaluation of slay composition in the sediments of the Mohamed Ben Abdelkrim El Khattabi Dam, Beni Bouayach, Northern Morocco

This research analyses and identifies clays from the Mohamed Ben Abdelkrim El Khattabi dam in Beni Bouayach, northern Morocco, to assess their suitability for various applications. The study employed X-ray diffraction (XRD), X-ray fluorescence, infrared spectroscopy, and physicochemical methods. Elemental analysis revealed high silicon and calcium levels alongside iron, aluminum, potassium, titanium, sulfur, manganese, and trace amounts of zinc, nickel, and chromium. These components suggest a clay composed mainly of montmorillonite, calcite, and quartz. The physicochemical characteristics included a neutral pH of 7.6, an average density of 2.04 g/cm3, a 16.01% moisture content, a swelling index above 0.65%, and a 0.64% loss on ignition. The XRD results support these findings. Infrared spectroscopy shows two prominent absorption bands: one at 3620 cm-1, linked to the -OH group, and another indicative of SiO4 and AlO4 tetrahedral units at approximately 400 cm-1 and 600 cm-1, respectively. The comprehensive analysis of this study reveals the clay composition and provides valuable insights into its potential industrial applications. Various elements and specific physicochemical properties suggest that these clays could be valuable in industries requiring specific mineral compositions and characteristics. This work lays the groundwork for future exploration and exploitation of these natural resources, highlighting their potential in diverse fields.

Fabrication and growth mechanism of t-selenium nanorods during laser ablation and fragmentation in organic liquids.

The process of forming selenium nanoparticles with various shapes and structures through laser ablation and fragmentation in various solvents has been explored. Laser ablation and laser fragmentation techniques were employed using nanosecond Nd:YAG second harmonic laser irradiation in 9 different working fluids, including water. The characteristics of the resulting nanoparticles were assessed using transmission electron microscopy (TEM), dynamic light scattering (DLS), spectroscopy, and X-ray diffraction (XRD) methods. Laser ablation and subsequent laser fragmentation of some organic solvents, such as ethanol, propanol-2, isobutanol, polyethylene glycol, and diethanolamine, have been found to produce trigonal selenium in the form of elongated nanorods approximately 1μm long and 200nm thick, with a well-defined crystal structure. In contrast, the use of deionized water, acetone, glycerol, and benzene as solvents results in the formation of spherical amorphous nanoparticles approximately 100nm in diameter. The polarity of the solvent molecules has been shown to influence the growth of crystalline selenium nanorods in solution during laser ablation and laser fragmentation. Generally, polar solvents hinder the growth of crystalline nanorods, due to interactions between selenium and solvent molecules. Nonpolar solvents, on the other hand, allow for laser fragmentation to reduce particle size and initiate the epitaxial growth of elongated, crystalline selenium nanorods.

Локальная структура и затвердевание расплавов Al-Ni-Co-РЗМ при высоком давлении (до 10 ГПа)

High pressure affects the solidification of glass-forming melts based on aluminum with transition and rare earth metals, allowing the synthesis of new metastable compounds that are stable for quite a long time under normal conditions. An attempt was made to connect high pressure with the glass-forming ability of melts. Using X-ray diffraction and electron microscopy methods, the effect of high pressure (up to 10 GPa) on the solidification of melts of complex multicomponent glass-forming alloys Al86Ni4Co4Gd6, Al86Ni2Co6Gd6, Al86Ni6Go4Gd2Er2, Al86Ni6Co4Gd2Tb2 with a temperature of 1800 K under conditions of rapid cooling was studied. The resulting samples are dense and homogeneous, with a fine-crystalline structure. Under high pressure conditions of 7-10 GPa, metastable crystalline phases were synthesized in alloys. Within the framework of the Ab-Initio Molecular Dynamics approach using density functional theory, the local structure of melts of selected alloys at low and high pressures was studied. The study of short-range order shows the presence of icosahedral clusters in melts, the formation of which is facilitated by rare earth metals. An increase in pressure from 0 to 10 GPa leads to an 8-fold increase in the concentration of icosahedra, resulting in the formation of a "percolation" cluster. It has been shown that the glass-forming ability of melts increases with increasing pressure, which affects the solidification processes. The arrangement of atoms in icosahedral clusters in melts promotes the formation of synthesized metastable crystalline phases in alloys.

Assessment of Pozzolanic Reactivity for Calcined Spent Bleaching Earth Ash (SBEA) using Strength Activity Index (SAI), Frattini Test and X-Ray Diffraction (XRD)

This research briefly investigates and compares three different and distinct methods of assessing the pozzolanic reactivity of a cementitious replacement material, Spent Bleaching Earth Ash (SBEA). SBEA is waste by-product of the edible oils refining industry and has some pozzolanic properties that could possibly be enhanced through calcination. Many methods have been developed to assess the reactivity of pozzolans and three of the most common ones were employed in this research; namely the Strength Activity Index (SAI), Frattini Test and X-Ray Diffraction (XRD) methods. These three methods were chosen as they measured reactivity based on fundamentally different methods; the SAI method relies on the mechanical strength of mortar cubes, XRD based it on the morphology of the material whilst the Frattini test looks into consumption of artificially-introduced calcium hydroxide by the pozzolan. This investigation allows correlation to be drawn between the three methods and at the same time, the effectiveness of calcination on SBEA can also be evaluated. The calcined SBEA was obtained through a 700°C heating process in the furnace at the for 4 hours. Both the SAI and Frattini tests were in good agreement and showed that the calcined SBEA consistently under-performed compared to uncalcined SBEA at both testing ages. This was, however, disputed by the XRD result which showed that SBEA benefitted from the calcination process as it lost over 7 % in crystallinity, hence making it more reactive. This outcome tells us that the selection of testing methods for pozzolanic reactivity must be done carefully and ideally several methods be used concurrently in order to correlate the results.

Novel ternary Zintl phosphide halides Ba3P5X (X = Cl, Br) with 1D helical phosphorus chains: synthesis, crystal and electronic structure.

Black single crystals of two novel ternary phosphide halides, Ba3P5Cl and Ba3P5Br, were grown using molten metal Pb-flux high-temperature reactions. These compounds were structurally characterized with the aid of the single-crystal X-ray diffraction (SCXRD) method at 100(2) K. The SCXRD shows that both compounds are isostructural and adopt a new structure type (space group R3̄c, No. 167, Z = 6) with unit cell parameters a = 14.9481(16) Å, c = 7.3954(11) Å and a = 15.045(4) Å, c = 7.537(3) Å for Ba3P5Cl and Ba3P5Br, respectively. Cl- and Br- anions are octahedrally coordinated by Ba2+ cations, thus composing a face-sharing 1D infinite chain 1∞[XBa3]5+ running along the [001] direction. Moreover, the crystal structures feature peculiar one-dimensional disordered infinite helical chains of 1∞P-, composed of partially occupied phosphorous atoms, each being a superposition of three symmetrical copies of the ordered phosphorus chain, with continuity along the c-axis. Ba3P5X (X = Cl, Br) compounds are charge-balanced heteroanionic Zintl phases according to the charge-partitioning scheme (Ba2+)3[P-]5X-. The presumed semiconducting behavior of both compounds corroborates well with the results of the electronic structure calculations performed with the aid of the TB-LMTO-ASA code.

Green synthesis of Ag2O & facile synthesis of ZnO and characterization using FTIR, bandgap energy & XRD (Scherrer equation, Williamson-Hall, size-train plot, Monshi- Scherrer model)

A typical study has been performed for synthesizing Ag2O and ZnO nanoparticles. In our case, aloe vera extract was used as a reducing agent for synthesizing Ag2O. This green synthesis of silver oxide used silver nitrate (AgNO3) as a precursor material. On the other hand, the direct precipitation method was used for synthesizing zinc oxide nanoparticles, in which the precursor materials used were zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and potassium hydroxide (KOH). Afterward, the characterization of these synthesized nanoparticles was done by the X-ray diffraction (XRD) method. Then, the crystal size, lattice strain, stress, and energy density of synthesized ZnO and Ag2O were determined by using XRD peak profile analysis. Among the various available models for determining these microstructural parameters, we explored the Scherrer model, the linear straight-line method of the Scherrer equation, the Monshi-Scherrer model, the Sahadat-Scherrer model, the Williamson-Hall model (including the uniform deformation model, the uniform stress deformation model, the uniform deformation energy density model), the size-strain plot method, the Halder-Wagner model, etc. By employing the crystal size values from these models, the accuracy and validity of crystals were also performed. The synthesized products were also characterized by the exploration of functional groups (by FTIR) and optical band gaps (by UV technique).

Membraneless ethanol fuel cell Pt-Sn-Re nano active catalyst on a mesoporous carbon support.

Herein, we report, for the first-time, mesoporous carbon-supported binary and ternary catalysts with different atomic ratios of Pt/MC (100), Pt-Sn/MC (50 : 50), Pt-Re/MC (50 : 50), Pt-Sn-Re/MC (80 : 10 : 10) and Pt-Sn-Re/MC (80 : 115 : 05) prepared using a co-impregnation reduction method as anode components for membraneless ethanol fuel cells (MLEFLs). Mechanistic and structural insights into binary Pt-Sn/MC, Pt-Re/MC and ternary Pt-Sn-Re/MC catalysts were obtained using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX) methods. In particular, chemical characterization via cyclic voltammetry, CO stripping voltammetry and chronoamperometry indicated that Pt-Sn-Re/MC (80 : 15 : 05) had better dynamics toward ethanol oxidation than Pt-Sn-Re/MC (80 : 10 : 10), Pt-Sn/MC (50 : 50) and Pt-Re/MC (50 : 50) catalysts. In terms of the single cell performance of the prepared catalysts, Pt-Sn-Re/MC (80 : 15 : 05) (31.5 mW cm-2) showed a higher power density and current density than Pt-Sn-Re/MC(80 : 10 : 10), Pt-Re/MC (50 : 50) and Pt-Sn/MC (50 : 50) at room temperature. The addition of Re into the binary Pt-Sn catalyst improved its electrical performance for ethanol oxidation in a membraneless ethanol fuel cell. As a result, the ternary-based Pt-Sn-Re/MC (80 : 15 : 05) catalyst demonstrated enhanced performance compared to monometallic and bimetallic catalysts in the ethanol oxidation reaction in a membraneless fuel cell.

The application of the X-ray diffraction method in the assessment of PT bridges

The present research focuses on the application of the X-ray diffraction method as a non-destructive testing technique to evaluate the stress level in tendons of post-tensioned (PT) elements, such as the ones characterizing large-span infrastructures. The knowledge of the stress level can provide relevant information about the maintenance condition of PT structures, highlighting the possible presence of criticisms. The X-ray methodology investigates the stress state on the near-surface region of the element: the resulting measure is therefore strongly influenced by the presence of residual stresses, that need to be somehow estimated. Residual stresses are induced by the manufacturing process: wires and strands are produced by applying a cold-drawing process to high-strength steels; the thermo-mechanical treatment is realized by imposing continuous heating on tensioned specimens. This latter process reduces the relaxation of cables and relieves the residual stresses induced by the drawing, that are, however, generated. The present work aims to determine the main factors affecting the measures, with a particular focus on residual stresses.

THERMODYNAMIC STUDY OF THE CdSb COMPOUND BY THE ELECTROMOTIVE FORCE MEASUREMENTS METHOD

Thermodynamic properties of CdSb binary compound were determined using an electromotive force measurement (e.m.f.) method with a liquid electrolyte in the ~300-450K temperatures interval. Equilibrium alloys from the CdSb+Sb phase region of the Cd-Sb system was analyzed by means of the e.m.f. measurements. Phase compositions of all samples were controlled using powder X-rays diffraction method. The partial molar functions of cadmium in alloys, the standard thermodynamic functions of formation, as well as the standard entropy of the CdSb compound were calculated. A comparative analysis of obtained results with literature data was performed.

Synthesis, Structural Investigation and Hirshfeld Surface Analyses of Two Imidazolinone based Heterocyclic Compounds

Two derivatives of imidazolinones, specifically DMPI {(Z)-5-(4-(dimethylamino)benzylidene)-2-methyl-3-(pyridin-3-ylmethyl)-3,5-dihydro-4H-imidazol-4-one} and MMPI {(Z)-5-(4-methoxybenzylidene)-2-methyl-3-(pyridin-3-ylmethyl)-3,5-dihydro-4H-imidazol-4-one} are reported which were synthesized under reflux conditions. Both the ligands are characterized with different analytical techniques including NMR spectroscopy, mass spectrometry, IR Spectroscopy. The subsequent elucidation of their solid-state structures was achieved through the single crystal X-ray diffraction method, providing detailed insights into their molecular arrangements. In the crystalline lattice, the asymmetric unit of DMPI comprises a solitary DMPI molecule, whereas MMPI reveals a more intricate arrangement with four molecules within its asymmetric unit. Various types of supramolecular interactions such as C–H…O, C–H…N, C–H…π and π…π interactions are observed in the x-ray structures where a trifurcated C-H…O bonds are also observed in both the ligands. All these interactions guide the formation of 3D supramolecular architecture in the solid-state of both compounds. Besides these, the 2D-fingerprint (2D-FP) and Hirshfeld surface analysis (HSA) computations were served to prove and quantify various supramolecular interactions within the crystal lattice.

Self-assembled Supramolecular Frameworks and Interaction Energy Studies of Acridine and Dihydroxynaphthalene based Cocrystals

Three cocrystals of acridine with 2,7-dihydroxynaphthalene (Ia and Ib) in two different polymorphs and 1,5-dihydroxynaphthalene (II) have been synthesized and characterized by single crystal x-ray diffraction method. Two polymorphs of acridine,2,7-dihydroxynaphthalene cocrystal crystallizes in same sapcegroup P-1 with different unit-cell parameters. In (Ia) the O‒H group form a syn-anti conformation whereas in (Ib) the O‒H group form an anti-anti conformation leads to the polymorphic structure of acridine, 2,7-dihydroxynaphthalene. This study reveals that the influence of π…π and C‒H…π interactions in the formation of one-, two-, and three-dimensional supramolecular frameworks when the classical hydrogen bonds such as O‒H…N and C‒H…O are limited to discrete motifs. The acridine molecules form continuous π…π stacking in the crystal structure of (Ia) and discrete π…π stacking in the crystal structure of (Ib) and (II). The conformational flexibility of the substituted hydroxy group has an influence in the supramolecular frameworks of the three-dimensional crystal structure. The intermolecular interaction energy calculation between the molecular pairs has been carried out to study the strength of the interaction and its dependence on the geometrical parameters.

Crystals of binary rare-earth metal germanides grown in molten indium. Synthesis and structural characterization of Nd3Ge5 and Lu3Ge4

Reported are the synthesis and the crystal structure determination of a new polymorphic form of the rare-earth metal germanide Nd3Ge5. As established by single-crystal X-ray diffraction methods, Nd3Ge5 crystallizes in a hexagonal crystal system with the space group P 2c (No. 190, Z = 2). The unit cell parameters are a = 6.9964(3) Å and c = 8.5820(8) Å. The structure is a derivative of the common structure type AlB2 (space group P6/mmm) where the atoms are stacked in a hexagonal close-packed manner. Digermanide NdGe2 is not known, rather the phase exists as NdGe2–x (x < 0) with a sizeable number of germanium vacancies. When the defect concentration reaches x = 1/3, the vacant Ge sites can undergo long-range ordering, resulting in the formation of Nd3Ge5 (=NdGe1.67). Therefore, the atomic arrangement can be described as a 6-fold superstructure of the AlB2 type structure (a' = a × 31/2 and c' = c × 2) with flat Ge layers, where every 6th Ge atom is missing; the Ge layers are stacked along the crystallographic c-axis, and are separated by hexagonal layers of rare-earth metal atoms. This is a new polymorph of Nd3Ge5, with the other form being orthorhombic and structurally related to another commonly observed structure, that of ThSi2. Besides the structure of Nd3Ge5, we also report the structure of the known phase Lu3Ge4, which has been previously identified from its powder diffraction pattern but never refined. Lu3Ge4 is isotypic with the rest of the REGe4 germanides (RE = Gd–Tm) and crystallizes in an orthorhombic crystal system with the space group Cmcm (No. 63, Z = 4) with unit-cell parameters a = 3.9591(8) Å; b = 10.429(2) Å; c = 14.019(3) Å.

Crystals of binary rare-earth metal germanides grown in molten indium. Synthesis and structural characterization of Nd3Ge5 and Lu3Ge4

Reported are the synthesis and the crystal structure determination of a new polymorphic form of the rare-earth metal germanide Nd3Ge5. As established by single-crystal X-ray diffraction methods, Nd3Ge5 crystallizes in a hexagonal crystal system with the space group P2c (No. 190, Z = 2). The unit cell parameters are a = 6.9964(3) Å and c = 8.5820(8) Å. The structure is a derivative of the common structure type AlB2 (space group P6/mmm) where the atoms are stacked in a hexagonal close-packed manner. Digermanide NdGe2 is not known, rather the phase exists as NdGe2–x (x < 0) with a sizeable number of germanium vacancies. When the defect concentration reaches x = 1/3, the vacant Ge sites can undergo long-range ordering, resulting in the formation of Nd3Ge5 (=NdGe1.67). Therefore, the atomic arrangement can be described as a 6-fold superstructure of the AlB2 type structure (a' = a  31/2 and c' = c  2) with flat Ge layers, where every 6th Ge atom is missing; the Ge layers are stacked along the crystallographic c-axis, and are separated by hexagonal layers of rare-earth metal atoms. This is a new polymorph of Nd3Ge5, with the other form being orthorhombic and structurally related to another commonly observed structure, that of ThSi2. Besides the structure of Nd3Ge5, we also report the structure of the known phase Lu3Ge4, which has been previously identified from its powder diffraction pattern but never refined. Lu3Ge4 is isotypic with the rest of the REGe4 germanides (RE = Gd–Tm) and crystallizes in an orthorhombic crystal system with the space group Cmcm (No. 63, Z = 4) with unit-cell parameters a = 3.9591(8) Å; b = 10.429(2) Å; c = 14.019(3) Å.

Fabrication of thiosemicarbazone-based Pd(II) complexes: structural elucidations, catalytic activity towards Suzuki-Miyaura coupling reaction and antitumor activity against TNBC cells.

Currently, there are many uses of metal complexes, especially in the fields of medicinal chemistry and catalysis. Thus, fabrication of new complexes which perform as a catalyst and chemotherapeutic drug is always a beneficial addition to the literature. Herein, we report three heterocyclic thiosemicarbazone-based Pd(II) complexes [Pd(HL1)Cl] (C1), [Pd(L2)(PPh3)] (C2) and [Pd(L3)(PPh3)]Cl (C3) having coligands Cl and PPh3. Thiosemicarbazone ligands (H2L1, H2L2 and HL3) and the complexes (C1-C3) were characterized methodically using several spectroscopic techniques. Single-crystal X-ray diffraction methods reveal that the structural environment around the metal center of C2 is square planar, while for C1 and C3 it is a slighty distorted square plane. The supramolecular network of compounds was built via hydrogen bonds, C-H⋯π and π⋯π interactions. Density functional theory (DFT) study of the structure of the complexes supports experimental findings. The application of these complexes as catalysts toward Suzuki-Miyaura coupling reactions has been examined with various aryl halides and phenyl boronic acid in PEG 400 solvent. The complexes displayed good biomolecular interactions with DNA/protein, with a binding constant value of the order of 105 M-1. C3 showed greater binding efficacy toward these biomolecules than the other complexes, which might be due to the cationic nature of C3. Furthermore, antitumor activity of the complexes was studied against the human triple-negative breast cancer (TNBC) cell line MDA-MB-231. It was found that C3 was more toxic (IC50 = 10 ± 2.90 μM) toward MDA-MB-231 cells than the other complexes. A known chemotherapeutic drug, 5-fluorouracil, was included as positive control. The programmed cell death mechanism of C3 was confirmed. Additionally, complex-induced apoptosis was confirmed and occurred via a mitochondria-dependent (intrinsic) pathway.

Синтез углеродных нанотрубок с помощью СВЧ излучения для модификации эластомера с улучшенной электро- и теплопроводностью

The paper presents a method of microwave influence on ferrocene C10H10Fe and graphite to obtain multilayer carbon nanotubes (MWCNTs) — designed to improve the electrical and thermophysical properties of silicon-graphite elastomer (Silagerm 8020). Diagnostics and characterisation of the synthesised MWCNTs were carried out by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. According to SEM data, it follows that the morphology of the synthesised MWCNTs has the form of filamentous formations intertwined in bundles with the diameter of individual MWCNTs from 40 to 60 nm and length up to several microns. At the same time, the surface of most of the MWCNTs is covered with a continuous layer of iron (Fe). The EDX method also confirmed the Fe and oxygen content on the surface of the MWCNTs. XRD method identified the presence of Fe in combination with carbon in the form of Fe3C iron carbide and pure Fe iron at 44.7°. The compound Fe3C, also referred to the active phase of Fe allowing the synthesis of MWCNTs. By increasing the concentration of MWCNTs in the elastomer, an increase in thermal conductivity with percolation transition was achieved at a concentration of 8 % MWCNTs. The maximum thermal conductivity of the nanomodified elastomer was 0.48 W/(m·°C), which corresponded to the mass concentration of MWCNTs equal to 8 wt.%. At the same time, the electrical conductivity of the composite, when the MWCNTs concentration was changed from 1 to 8 %, increased in the range from 4·10–5 to 2.4 cm·cm–1 and is also due to the percolation of MWCNTs in the elastomer matrix.

The Structural Basis of DL0410, a Novel Multi-Target Candidate Drug for the Treatment of Alzheimer’s Disease

Alzheimer’s disease (AD) is a complicated disease for which there are still no ideal one-target drugs, while multi-target drugs are closer to ideal drugs and will provide new solutions for the clinical treatment of AD. DL0410 is a promising multi-target drug candidate for AD treatment that is not only a significant inhibitor against both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) but also an antagonist of histamine H3 receptor (H3R), and its therapeutic efficacy in treating cognitive dysfunction has been validated in a series of AD-related animal models, including scopolamine-induced mice, D-galactose-induced and Aβ-induced mice, and APP/PS1 and SAMP8 mice. Although the structure of DL0410 has been analyzed using various detection techniques, such as MS and NMR, its three-dimensional crystal structure still requires further confirmation. In this study, the crystal of DL0410 was grown in aqueous solution, and its structure was detected using the X-ray diffraction method. The crystal data, atomic coordinates, bond lengths, angles, and hydrogen bonds of DL0410 were obtained. Its stability was proven by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Based on this study, the molecular docking of DL0410 with AChE, BuChE, and H3R was performed to uncover their interaction mechanisms and explain their bioactivities. This study provides important information for new multi-target drug design and the research and development of new drugs for AD treatment.