Synthesis, structural, and optical behavior of erbium-doped silicophosphate glasses for photonics applications.

Erbium-incorporated silicophosphate glasses are very desirable in principal sectors such as photonics, optoelectronics, lasers, and illuminating diodes. The focus of the current investigation has been on determining how the erbium dopant affects the optical, physical, and structural characteristics of the silicophosphate-based glasses. The pure silicophosphate glasses and doped with various contents of erbium were prepared by the sol-gel process in this work. The noncrystalline character of the glasses synthesized was confirmed by the XRD patterns that were obtained. The optical measurement showed that the addition of trivalent erbium ions resulted in an increase in the refractive index of the samples and a decrease in their energy band gap values. It demonstrated the presence of P-O-P linkage stretching vibration modes that were both symmetrical and asymmetrical, P-O in PO4 bending vibration modes, OH group elongating and flexure vibrations, and P-O-H water absorption in glasses. The theoretical values of the optical basicity (Ʌth) increased from 0.465 to 0.472, while the values of the interaction parameter (A) decreased from 0.218 to 0.214 Š- 3 $$ {\overset{\ocirc }{\mathrm{A}}}^{-3} $$ . Silicophosphate glasses doped with trivalent erbium ions show promise as optoelectronic and optical filter system materials.

Effect of Cold-Rolling Deformation on the Microstructural and Mechanical Properties of a Biocompatible Ti-Nb-Zr-Ta-Sn-Fe Alloy.

The primary focus of the current paper centers on the microstructures and mechanical properties exhibited by a Ti-30Nb-12Zr-5Ta-2Sn-1.25Fe (wt. %) (TNZTSF) alloy that has been produced through an intricate synthesis process comprising cold-crucible induction in levitation, carried out in an atmosphere controlled by argon, and cold-rolling deformation (CR), applying systematic adjustments in the total deformation degree (total applied thickness reduction), spanning from 10% to 60%. The microstructural characteristics of the processed specimens were investigated by SEM and XRD techniques, and the mechanical properties by tensile and microhardness testing. The collected data indicate that the TNZTSF alloy's microstructure, in the as-received condition, consists of a ß-Ti phase, which shows polyhedral equiaxed grains with an average grain size close to 82.5 µm. During the cold-deformation processing, the microstructure accommodates the increased applied deformation degree by increasing crystal defects such as sub-grain boundaries, dislocation cells, dislocation lines, and other crystal defects, powerfully affecting the morphological characteristics. The as-received TNZTSF alloy showed both high strength (i.e., ultimate tensile strength close to σUTS = 705.6 MPa) and high ductility (i.e., elongation to fracture close to εf = 11.1%) properties, and the computed ß-Ti phase had the lattice parameter a = 3.304(7) Å and the average lattice microstrain ε = 0.101(3)%, which are drastically influenced by the applied cold deformation, increasing the strength properties and decreasing the ductility properties due to the increased crystal defects density. Applying a deformation degree close to 60% leads to an ultimate tensile strength close to σUTS = 1192.1 MPa, an elongation to fracture close to εf = 7.9%, and an elastic modulus close to 54.9 GPa, while the computed ß-Ti phase lattice parameter becomes a = 3.302(1) Å.

Suillusgrevillei and Suillus luteus promote lead tolerance of Pinus tabulaeformis and biomineralize lead to pyromorphite.

Lead (Pb) is a hazardous heavy metal that accumulates in many environments. Phytoremediation of Pb polluted soil is an environmentally friendly method, and a better understanding of mycorrhizal symbiosis under Pb stress can promote its efficiency and application. This study aims to evaluate the impact of two ectomycorrhizal fungi (Suillus grevillei and Suillus luteus) on the performance of Pinus tabulaeformis under Pb stress, and the biomineralization of metallic Pb in vitro. A pot experiment using substrate with 0 and 1,000 mg/kg Pb2+ was conducted to evaluate the growth, photosynthetic pigments, oxidative damage, and Pb accumulation of P. tabulaeformis with or without ectomycorrhizal fungi. In vitro co-cultivation of ectomycorrhizal fungi and Pb shots was used to evaluate Pb biomineralization. The results showed that colonization by the two ectomycorrhizal fungi promoted plant growth, increased the content of photosynthetic pigments, reduced oxidative damage, and caused massive accumulation of Pb in plant roots. The structural characteristics of the Pb secondary minerals formed in the presence of fungi demonstrated significant differences from the minerals formed in the control plates and these minerals were identified as pyromorphite (Pb5(PO4)3Cl). Ectomycorrhizal fungi promoted the performance of P. tabulaeformis under Pb stress and suggested a potential role of mycorrhizal symbiosis in Pb phytoremediation. This observation also represents the first discovery of such Pb biomineralization induced by ectomycorrhizal fungi. Ectomycorrhizal fungi induced Pb biomineralization is also relevant to the phytostabilization and new approaches in the bioremediation of polluted environments.

Facile Synthesis of Silver Nanoparticles From Sustainable Sargassum sp. Seaweed Material and Its Anti-inflammatory Application.

Background Sustainable and environmentally friendly methods of producing nanoparticles are now being investigated by scientists. Because there are so many marine renewable resources, scientists are focusing their attention on studying seagrass, seaweed, mangroves, marine macroalgae, and microalgae. An exciting new frontier in research involves the synthesis of nanoparticles using extracts from seaweed. Seaweed extracts are utilized to synthesize silver nanoparticles (Ag NPs), which serve as both reducing and stabilizing agents. Seaweed extracts possess bioactive substances like proteins, polysaccharides, and polyphenols that enable them to effectively convert silver (Ag+) ions into Ag NPs. Ag NPs derived from Sargassum seaweed have played an essential role in improving the anti-inflammatory properties of seaweed extracts. This study aimed to investigate the biosynthesis of Ag NPs from Sargassum seaweed and evaluate their anti-inflammatory properties. Materials and methods About 50 g of seaweed samples were mixed with 100 mL of distilled water and stirred for 24 hours. Additionally, 1.2 g of silver nitrate (0.120 M) was dissolved in 60 mL of distilled water to make a silver (Ag) solution. A 60 mL solution of silver nitrate (AgNO3) was mixed with a 40 mL solution of seaweed extract in water, and the mixture was stirred with a stirrer for 24 hours. A UV spectrophotometer was used to regularly monitor the reduction of Ag+ ions in the solution. Ag NPs were purified using a sequence of centrifugation steps with a duration of 10 minutes at a speed of 2500 revolutions per minute (rpm). To remove moisture from the water-suspended nanoparticles, they were vacuum-dried for 24 hours.  Results The synthesis of Ag NPs from seaweed extract resulted in a noticeable change in the color of the mixture, which went from pale to brown. The alteration in color signifies the reduction of AgNO3 to Ag+ ions, facilitating the creation of Ag NPs. X-ray diffraction (XRD) measurement verified the remarkable crystallinity of the synthesized Ag NPs. Field emission scanning electron microscopy (FESEM) images indicated a spherical, homogeneous structure. The Ag NPs derived from seaweed exhibited significant anti-inflammatory characteristics. Conclusion Utilizing Sargassum sp. seaweed in the biological synthesis of Ag NPs shows promise to develop nanomaterials that can exhibit anti-inflammatory effects. This technique has benefits, such as being environmentally friendly and cost-efficient. Additional research in this area is essential for effectively exploiting the potential of Ag NPs in anti-inflammatory activity.

Synergistic effects of hybrid microfibers on mechanical, thermal, and microstructural characterization of nanocomposites.

The use of geopolymers (GP) in cementitious composites provides a solution to reduce the significant carbon emissions associated with conventional cement production, thereby advancing environmentally friendly concrete construction practices. The promise of hybrid fiber-reinforced fly ash (FA)-based GP (HFGP) composites that combine microfibers and nanoparticles has not yet been fully comprehended. This research aims to enhance the mechanical and microstructural properties of HFGP blends by varying the proportion of nano calcium carbonate ( n - C a C O 3 ). The production of HFGP involved the use of two types of fibers: 1% carbon fibers and 0.5% basalt fibers. To achieve HFGP blends with a consistent fiber ratio, we incorporated four different levels of n - C a C O 3 , comprising 1%, 2%, 3%, and 4% of the mixture. The analysis of fractured samples encompassed microstructural and mineralogical characterization, which was conducted using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analysis. The results unveiled that the HFGP blend containing 3% n - C a C O 3 exhibited the highest levels of hardness, compressive strength, toughness modulus, and flexural strength while the use of 2% n - C a C O 3 produced the highest results for fracture toughness and impact strength. SEM analysis illustrated that n - C a C O 3 had a significant positive impact on the microstructure of GP. A considerable rise in hump intensity between 20 and 40 °C ( 2 θ ) was also seen in the XRD examination, indicating that calcium silicate hydrate (CSH) had formed after the primary binder, such as sodium aluminosilicate hydrate (NASH), had been present. The stretching of O-H bonds in water molecules was also seen in the HFGP spectra at 3399, 3436, 3436, and 3438 cm-1. Due to the higher water content in the HFGP network, which may influence the material's strength, these bands were more apparent and larger in specimens with additions of nanoparticles and hybrid fibers.

1,2-Bis(triazolyl)tetraphenyldigermanes: Synthesis, Structure and Properties.

Using the [3+2] cycloaddition reaction of [HC≡C-GePh2 -]2 (1) and a number of RCH2 N3 , this work described the synthesis of a series of novel heterocyclic digermanes, bitriazoles [1,4-C2 HN3 (CH2 R)GePh2 -]2 , 2-12 (R=Ph, p-Tol, p-C6 H4 NMe2 , p-C6 H4 OMe, p-C6 H4 Br, m-C6 H4 NO2 , 2-Naphth, CH2 -p-OC6 H4 CHO, CH2 -p-OC6 H4 COOMe, CH2 P(O)(OEt)2 , COOEt), difficult to produce by other methods. The structural peculiarities of these compounds were studied in detail by NMR spectroscopy and by XRD analysis (for 6, 9 and 10). The properties of 1-12 were studied by UV/vis and luminescence emission spectroscopy, electrochemistry and DFT calculations, indicating an effective conjugation in their molecules.

Structural Motifs in Aryl Organogermanium Ge-O Derivatives for Material Design.

The aim of this work was to understand the main structural features and ways of formation of Ge-O bonds in organogermanium compounds under the conditions of ArnGeHal4-n (Hal = halide) hydrolysis. The structural types of these compounds were considered, providing 11 blocks (A-K). The molecular structures of the novel compounds [(p-FC6H4)3Ge]2O (1), [(p-F3CC6H4)3Ge]2O (2), and cyclo-[(p-F3CC6H4)2GeO]4 (3) were studied through XRD (X-ray diffraction) analysis. The molecular structure of [(p-F3CC6H4)3GeO]4Ge (4), representing a novel structural type, was also investigated. The data presented in this study will be important in the design of materials with useful properties based on group 14 element derivatives with element-oxygen bonding.

Foetidumins A-D, and other chemical constituents from Helichrysum foetidum (L.) Moench (Asteraceae) with antiparasite activity.

The phytochemical investigation of the MeOH and CH2Cl2-MeOH (1:1) extracts from the flowers and twigs of Helichrysumfoetidum (L.) Moench (Asteraceae), which showed antileishmanial and antiplasmodial activities during the preliminary screening, led to the isolation of four undescribed compounds, including two ent-beyer-15-ene-type diterpenoids, foetidumins A (1) and B (2), one flavonoid, foetidumin C (3) and one chalcopyrone, foetidumin D (4). Additionally, fourteen known compounds comprising, two ent-beyer-15-ene-type diterpenoids (5-6), six flavonoids (7-12), two steroids (13-14), three triterpenoids (15-17), and one glyceryl monostearate (18) were also isolated. The chemical structures of foetidumins A-D were fully elucidated by analyses of their spectroscopic data. The structure and the stereochemistry of foetidumin A (1) were confirmed by SC-XRD analyses. Among the tested compounds, foetidumin C (3), erythroxylol A (6), and kaempferol (7) displayed the highest antileishmanial potency with IC50 values of 13.0, 11.8, and 11.1 µM, respectively. Foetidumin C (3) had no cytotoxicity toward Vero cells with the selectivity index > 3.59. Meanwhile, extracts of flowers and twigs had higher activity against Plasmodium falciparum chloroquine-sensitive (Pf3D7) strain with IC50 values of 3.66 and 10.52 µg/mL, respectively.

Green synthesis of Fe3O4 nanoparticles using Alliaceae waste (Allium sativum) for a sustainable landscape enhancement using support vector regression.

The synthesis of metal nanoparticles using green chemistry methods has gained significant attention in the field of landscape enhancement. Researchers have paid close attention to the development of very effective green chemistry approaches for the production of metal nanoparticles (NPs). The primary goal is to create an environmentally sustainable technique for generating NPs. At the nanoscale, ferro- and ferrimagnetic minerals such as magnetite exhibit superparamagnetic properties (Fe3O4). Magnetic nanoparticles (NPs) have received increased interest in nanoscience and nanotechnology due to their physiochemical properties, small particle size (1-100 nm), and low toxicity. Biological resources such as bacteria, algae, fungus, and plants have been used to manufacture affordable, energy-efficient, non-toxic, and ecologically acceptable metallic NPs. Despite the growing demand for Fe3O4 nanoparticles in a variety of applications, typical chemical production processes can produce hazardous byproducts and trash, resulting in significant environmental implications. The purpose of this study is to look at the ability of Allium sativum, a member of the Alliaceae family recognized for its culinary and medicinal benefits, to synthesize Fe3O4 NPs. Extracts of Allium sativum seeds and cloves include reducing sugars like glucose, which may be used as decreasing factors in the production of Fe3O4 NPs to reduce the requirement for hazardous chemicals and increase sustainability. The analytic procedures were carried out utilizing machine learning as support vector regression (SVR). Furthermore, because Allium sativum is widely accessible and biocompatible, it is a safe and cost-effective material for the manufacture of Fe3O4 NPs. Using the regression indices metrics of root mean square error (RMSE) and coefficient of determination (R2), the X-ray diffraction (XRD) study revealed the lighter, smoother spherical forms of NPs in the presence of aqueous garlic extract and 70.223 nm in its absence. The antifungal activity of Fe3O4 NPs against Candida albicans was investigated using a disc diffusion technique but exhibited no impact at doses of 200, 400, and 600 ppm. This characterization of the nanoparticles helps in understanding their physical properties and provides insights into their potential applications in landscape enhancement.

Microstructural and Electrochemical Influence of Zn in MgCaZn Biodegradable Alloys.

In recent years, biodegradable materials have included magnesium alloys with homogenous disintegration and a controllable degradation rate. Utilized in medical applications, biodegradable materials based on magnesium have been widely explored throughout the years. It is well-known that alloying Mg with biocompatible and non-toxic elements increases the biodegradability of surgical alloys. The purpose of this study was to examine the microstructure and the electrochemical response (corrosion resistance) of a new experimental Mg-based biodegradable alloy-Mg-0.5%Ca with additions of Zn as follows: 0.5, 1.5, and 3.0 wt.% in order to control the corrosion rate. Immersion tests were performed for different periods in a simulated body fluid electrolyte solution at 37 °C, and the mass loss was appreciated in order to calculate the corrosion rate (CR). The investigation led to the discovery of a dendritic Mg solid solution, a lamellar Mg2Ca compound, and a MgZn2 intermetallic phase. Scanning electron microscopy, optical microscopy, and energy dispersive spectroscopy were used for surface analysis after the immersion and electro-corrosion resistance tests. The metallic and ceramic compounds that detached themselves from the sample and passed into the solution were evaluated using the SEM-EDS system. All samples presented a generalized electro-corrosion with anodic and cathodic reactions of similar intensity. The corrosion rate was similar regardless of the percentage of zinc, with a smaller value for a higher than 3 wt.% Zn percentage based on the more protective zinc oxide that appeared on the surface.

Microstructural characterization data for nuclear graphite samples generated during tribology testing in argon.

This article contains microstructural characterization data related to the research article 'Self-lubrication of Nuclear Graphite in Argon at High Temperature', published in Tribology International. Digital, optical, and scanning electron micrographs are collected on the pebble and disk samples generated in the tribological tests and in their corresponding reference samples. Surface roughness measurements of the test and control samples are performed using the 3D-depth composition feature of the digital microscope. X-ray diffraction and Raman spectra of the test and reference samples are acquired and peak-fitted according to published literature on nuclear graphite characterization. Plots of the peak-fitted spectra are included in this article; the full list of peak-fitting parameters is provided in the linked data repository.

Growing, Structure and Optical Properties of LiNbO3:B Crystals, a Material for Laser Radiation Transformation.

Physical and chemical properties have been studied in lithium niobate (LiNbO3, LN) crystals grown by Czochralski from a boron doped melt. Optical uniformity and optical damage resistance of LiNbO3:B crystals have been compared with control crystals of nominally pure congruent (CLN) and near-stoichiometric (NSLN K2O) composition. LiNbO3:B crystals structure has been studied. Studied LiNbO3:B crystals have been grown from differently synthesized charges. The charges have been synthesized from a mixture Nb2O5:B-Li2CO3 using homogeneously doped Nb2O5:B precursor (sample 1, (B) = 0.0034 wt% in the charge) and by a direct solid phase synthesis from Nb2O5-Li2CO3-H3BO3 mixture (sample 2, (B) = 0.0079 wt% in the charge). Only traces of boron (10-5-10-4 wt%) have been detected in the samples. We have established that concentration of anti-site defects NbLi is lower in both LiNbO3:B than in CLN crystals. XRD analysis has confirmed that B3+ cations localize in faces of tetrahedral voids O4 of LN structure. The voids act as buffers at the anion sublattice distortion. Sample 1 has been shown to have a structure closer to NSLN K2O crystal than sample 2. We have also shown that the chemical purity of LN crystal increases compared to the melt purity because boron creates strong compounds with impurities in the melt system Li2O-Nb2O5-B2O3. Metals impurities thus stay in the melt and do not transfer to the crystal.

Characterization of solid biomass briquette biofuel from the wastes of Senna auriculata and Ricinus communis using Tapioca starch for sustainable environment.

Biomass energy contributes nearly 14% of the total global energy. Therefore, biomass briquettes can be effectively considered an alternate source of fossil fuels. The present study aims at utilizing Senna auriculata and Ricinus communis waste generated locally for the production of biomass briquettes with 10% of tapioca starch as binder. The biomass wastes are blended at various proportions such as 0:100 (S1), 25:75 (S2), 50:50 (S3), 75:25 (S4) and 100:0 (S5) respectively, and the concentration of binder was maintained to be constant. The characterization of the prepared biomass briquettes includes the analysis of physical characteristics, proximate analysis, elemental analysis, SEM analysis, thermogravimetric analysis, differential scanning calorimetric analysis and XRD analysis. The results of the proximate analysis have revealed that the biomass briquettes possess lower percentage in terms of moisture content, ash content, sensible fixed carbon and high percentage of volatile matter content. Energy dispersive X-ray analysis has shown that the carbon and oxygen are the major elements for all the biomass briquettes. SEM analysis has revealed that the surface of the biomass briquettes is identified with irregular surface, lumps, cavities and few deposits of carbon particles. Thermogravimetric analysis and DSC analysis have reconfirmed the spontaneous burning characteristics of biomass briquettes. XRD analysis has proved that the bonding between each element present in the biomass briquettes is either monoclinic, tetragonal, orthorhombic or anorthic.

Spectroscopic and crystallographic analysis of nephrite jade gemstone using laser induced breakdown spectroscopy, Raman spectroscopy, and X-ray diffraction.

The elemental composition, mineral phases, and crystalline structure of nephrite jade were investigated using calibration-free laser-induced breakdown spectroscopy (CF-LIBS), Raman spectroscopy, and X-ray diffraction (XRD). For compositional analysis, the laser-induced plasma was generated on the surface of nephrite jade. The plasma emissions were then acquired and analyzed, which revealed several elements in the sample, including Si, Mg, Ca, Li, Fe, Al, Na, K, and Ni. The plasma temperature was extracted from the Boltzmann plot before and after two-step self-absorption correction, and used in CF-LIBS calculations to get the elemental concentration. After self-absorption correction, the quantitative results obtained using CF-LIBS were found to be in close agreement with ICP-OES. The Raman spectrum of nephrite jade exhibits Si-O and M-OH stretching vibrations in the regions of 100 cm-1 to 1200 cm-1 and 3600 cm-1 to 3700 cm-1, respectively, whereas the XRD spectrum revealed the monoclinic crystalline phase of tremolite.

Magnetization Processes in Metallic Glass Based on Iron of FeSiB Type.

In the present paper, the magnetization processes in amorphous alloys based on iron are discussed in detail. Our main goal was to measure the stabilization energy connected with the presence of microvoids (frozen during rapid cooling from the liquid phase) and to determine the interaction energy of relaxators with spontaneous magnetization vector (the so-called wN Neel) for amorphous Fe78Si13B9 alloys. A structural analysis of the alloys using X-ray measurements at the subsequent stages of crystallization was also performed.

New O- and N-N-Bridging Complexes of Tc(V), the Role of the Nitrogen Atom Position in Aromatic Rings: Reaction Mechanism, Spectroscopy, DTA, XRD and Hirshfeld Surface Analysis.

In this work, O- and N-N-bridging complexes of technetium (V), previously known only for rhenium, were obtained for the first time. Tc(V) complexes with pyridazine (pyd), 1,2,4-triazole (trz), 3,5-dimethylpyrazole (dmpz) and pyrimidine (pyr) were obtained. In three complexes [{TcOCl2}2(µ-O)(µ-pyd)2], [{TcOCl2}2(µ-O)(µ-trz)2]·Htrz·Cl and [{TcO(dmpz)4}(µ-O)(TcOCl4)] two technetium atoms are linked by a Tc-O-Tc bond, and in the first two, Tc atoms are additionally linked by a Tc-N-N-Tc bond through the nitrogen atoms of the aromatic rings. We determined the role of nitrogen atom position in the aromatic ring and the presence of substituents on the formation of such complexes. For the first time, a reaction mechanism for the formation of such complexes was proposed. This article details the crystal structures of four new compounds. The work describes in detail the coordination of Tc atoms in the obtained structures and the regularities of the formation of crystal packings. The spectroscopic properties of the obtained compounds and their mother solutions were studied. The decomposition temperatures of the described complexes were determined. An assumption was made about the oligomerization of three-bridged complexes based on the results of mass spectrometry. Through the analysis of non-valent interactions in the structures, π-stacking, halogen-π and CH-π interactions were found. An analysis of the Hirshfeld surface for [{TcOCl2}2(µ-O)(µ-pyd)2], [{TcOCl2}2(µ-O)(µ-trz)2] and their rhenium analogues showed that the main contribution to the crystalline packing is made by interactions of the type Hal···H/H···Hal (45.4-48.9%), H···H (10.2-15.8%), and O···H/H···O (9.4-16.5%).

Temperature Measurement during Abrasive Water Jet Machining (AWJM).

This study was undertaken to look for confirmation that heat transfer induced by abrasive water jet machining (AWJM) affects the microstructure of the material cut. The structure of S235JR carbon steel used in the experiments was reported to change locally in the jet impact zone due to the high concentration of energy generated during cutting with the abrasive water jet. It is assumed that some of the energy is transferred into the material in the form of heat. This is particularly true for materials of considerable thickness with a high thermal conductivity coefficient when cutting is performed at low speeds or with high abrasive consumption. The literature on the subject suggests that in AWJM there is little or no thermal energy effect on the microstructure of the material cut. The research described here involved the measurement of the cutting temperature with thermocouples placed at four different distances from the edge. The distances were measured using computed tomography inspection. The thermocouples used in the tests were capable of detecting temperatures of up to 100 °C. Locally, temperatures at the edge may reach much higher values. The results of the X-ray diffraction qualitative phase analysis reveal that locally the temperatures may be much higher than the eutectoid temperature. Phase changes occurred along the edge since austenite was observed. This suggests that the temperature in the jet impact zone was much higher than the eutectoid temperature. Optical microscopy was also employed to study the material microstructure. Finally, the material nanohardness was determined.

Novel Synthesis Methods of New Imidazole-Containing Coordination Compounds Tc(IV, V, VII)-Reaction Mechanism, Xrd and Hirshfeld Surface Analysis.

In this work, we have proposed two new methods for the synthesis of [TcO2L4]+ (where L = imidazole (Im), methylimidazole (MeIm)) complexes using thiourea (Tu) and Sn(II) as the reducing agents. The main and by-products of the reactions were determined, and possible reaction mechanisms were proposed. We have shown that the reduction of Tc(VII) with thiourea is accompanied by the formation of the Tc(III) intermediate and further oxidation to Tc(V). The reaction conditions' changing can lead to the formation of Tc(VII) and Tc(IV) salts. Seven new crystal structures are described in this work: Tc(V) complexes, salts with Tc(VII) and Tc(IV) anions. For the halide salts of Tu the cell parameters were determined. In all of the obtained compounds, except for [TcO2(MeIm)4]TcO4, there are π-stacking interactions between the aromatic rings. An increase in the anion size lead to weakening of the intermolecular interactions. The halogen bonds and anion-π interactions were also found in the hexahalide-containing compounds. The Hirshfeld surface analysis showed that the main contribution to the crystal packing is created by the van der Waals interactions of the H···H type (42.5-55.1%), H···C/C···H (17.7-21.3%) and hydrogen bonds, which contribute 15.7-25.3% in total.

Design, synthesis and characterization of novel Ni(II) and Cu(II) complexes as antivirus drug candidates against SARS-CoV-2 and HIV virus.

This paper describes the structure-based design, synthesis and anti-virus effect of two new coordination complexes, a Ni(II) complex [Ni(L)2] (1) and a Cu(II) complex [Cu(L)2] (2) of (E)-N-phenyl-2-(thiophen-2-ylmethylene) hydrazine-1-carbothioamide(HL). The synthesized ligand was coordinated to metal ions through the bidentate-N, S donor atoms. The newly synthesized complexes were characterized by various spectroscopic and physiochemical methods, powdered XRD analysis and also X-ray crystallography study. Ni(II) complex [Ni(L)2](1) crystallize in orthorhombic crystal system with the space group Pbca with four molecules in the unit cell (a = 9.857(3) Å, b = 7.749(2) Å, c = 32.292(10) Å, α = 90°, ß = 90°, γ = 90°, Z= 4) and reveals a distorted square planar geometry. A Hirshfeld surface and 2D fingerprint plot has been explored in the crystal structure of Ni(II) complex [Ni(L)2] (1). Energy framework computational analysia has also been explored. DFT based calculations have been performed on the Schiff base and its metal complexes to study the structure-property relationship. Furthermore, the molecular docking studies of the ligand and its metal complexes with SARS-CoV-2 virus (PDB ID: 7BZ5) and HIV-1 virus (PDB ID: 6MQA) are also investigated. The molecular docking calculations of the Ni(II) complex [Ni(L)2] (1) and a Cu(II) complex [Cu(L)2] (2) with SARS-CoV-2 virus revealed that the binding affinities at inhibition binding site of receptor protein are 9.7 kcal/mol and -9.3 kcal/mol, respectively. The molecular docking results showed that the binding affinities of Ni(II) complex (1) and Cu(II) complex (2) against SARS-CoV-2 virus were found comparatively higher than the HIV-1 virus (-8.5 kcal/mol and -8.2 kcal/mol, respectively). As potential drug candidates, Swiss-ADME predictions analyses are also studied and the results are compared with Chloroquine (CQ) and Hydroxychloroquine (HCQ) as anti-SARS-CoV-2 drugs.

Oligoorganogermanes: Interplay between Aryl and Trimethylsilyl Substituents.

Derivatives of main group elements containing element-element bonds are characterized by unique properties due to σ-conjugation, which is an attractive subject for investigation. A novel series of digermanes, Ar3Ge-Ge(SiMe3)3, containing aryl (Ar = p-C6H4Me (1), p-C6H4F (2), C6F5 (3)) and trimethylsilyl substituents, was synthesized by the reaction of germyl potassium salt, [(Me3Si)3GeK*THF], with triarylchlorogermanes, Ar3GeCl. The optical and electronic properties of such substituted oligoorganogermanes were investigated spectroscopically by UV/vis absorption spectroscopy and theoretically by DFT calculations. The molecular structures of compounds 1 and 2 were studied by XRD analysis. Conjugation between all structural fragments (Ge-Ge, Ge-Si, Ge-Ar, where Ar is an electron-donating or withdrawing group) was found to affect the properties.