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This work uses green sustainable reactions twice. Firstly, it is microwave synthesis: 2,4,6-tribiphenyl-4-yl-1,3,5-triazine and similar compounds were prepared in a closed microwave reactor in n-octane by the Friedel-Crafts reaction. Second, a hybrid electrocatalyst for the highly demanded electrochemical reaction of nitrate reduction to ammonia (NO 3 RR) was prepared based on this material. This reaction has great potential to replace the energy-intensive Haber-Bosch process, and in addition, has independent value for the elimination of nitrate contamination of water resources. As shown in the work, microwave synthesis is an eco-friendly method for the synthesis of complex organic compounds; fast, selective and with a high yield of the target product. The electrocatalyst deposited on the graphite electrode consisted of a layer of 2,4-bis([1,1'-biphenyl]-4-yl)-6-hydroxy-1,3,5-triazine and related compounds coated with cobalt oxide. The hybrid catalyst was firmly retained on the graphite electrode during NO 3 RR and the material showed impressive stability with almost no decrease in catalytic activity even after the fifth cycle. Both 2,4-bis([1,1'-biphenyl]-4-yl)-6-hydroxy-1,3,5-triazine and the catalyst based on this substance were characterized by SEM, XPS, XRD, UV-vis spectra, cyclic (and linear) voltammetry, and chronoamperometry. This work can serve as a starting point for the development of stable and durable electrocatalysts for NO 3 RR using triazine derivatives., (© 2024 Wiley-VCH GmbH.)

The analysis of decay chains starting at superheavy nuclei 293Ts and 289Mc is presented. The spectroscopic properties of nuclei identified during the experiments using the 249Bk+48Ca and 243Am+48Ca reactions studied at the gas-filled separators DGFRS, TASCA and BGS are considered. We present the analysis of decay data using widely adopted statistical methods and applying them to the short decay chains of parent odd-Z nuclei. We find out that the recently suggested method of analyzing decay chains by Forsberg et al may lead to questionable conclusions when applied for the analysis of radioactive decays. Our discussion demonstrates reasonable congruence of α-particle energies and decay times of nuclei assigned to isotopes 289Mc, 285Nh and 281Rg observed in both reactions. [ABSTRACT FROM AUTHOR]

Forsberg and Leino (2019 J. Phys. G: Nucl Part Phys46 018001) question the validity of criticism (2017 J. Phys. G: Nucl. Part. Phys.44 075107) of the method proposed by Forsberg et al (2016 Nucl. Phys. A 953 117). In this reply, we show that this method is based on unclear principles and its implementation leads to the results that contradict the conclusions following from mathematical statistics. [ABSTRACT FROM AUTHOR]

Post-synthetic modification of proton-conducting metal–organic frameworks (MOFs) by loading small molecules capable of generating protons into pores is an efficient approach for developing a new type of material with improved ionic conductivity. Herein, the synthesis, characterization and proton conductivity of a novel electroneutral MOF based on palladium(II) meso-tetrakis(4-(phosphonatophenyl))porphyrinate, IPCE-1Pd, are reported. The exposure of the obtained framework to imidazole by the diffusion vapor method has surprisingly led to its complete crystal-to-crystal MOF-to-HOF transformation, resulting in the formation of a novel hydrogen-bonded organic framework (HOF) IPCE-1Pd_Im, which is the first example of such kind of structural change among all known MOFs. This modification has led to an almost 25-fold increase in the proton conductivity in comparison with the pristine MOF, reaching up to 6.54 × 10−3 S cm−1 at 85 °C and 95% relative humidity, which is one of the highest values among all known porphyrin-based HOFs. [ABSTRACT FROM AUTHOR]

The new homochiral 1D metal–organic coordination polymer {Cu[bdc-(N-MePro)H2O]·0.25H2O}n was synthesized using 2-[(1-methyl- L -prolyl)amino]terephthalic acid, which was obtained for the first time. The unique crystal structure of the new compound was determined using powder X-ray diffraction. The catalytic performance of {Cu[bdc-(N-MePro)H2O]·0.25H2O}n in the asymmetric ring opening reactions of styrene oxide and cyclohexene oxide with aniline was evaluated. [ABSTRACT FROM AUTHOR]

The GRAND universal gas-filled separator, located at the Factory of Super-Heavy Elements in the Flerov Laboratory of Nuclear Reactions (FLNR), Joint Institute for Nuclear Research, has been created and put into operation. The separator can be used both in experiments on α, β, and γ spectroscopy of isotopes of heavy and superheavy elements and in experiments on the chemical properties of superheavy elements as a preseparator. The results of the first experimental tests of the GRAND separator are presented. The possibility of effectively carrying out experiments both on a "physical" detection system and on a "chemical" installation has been demonstrated. [ABSTRACT FROM AUTHOR]

Raltegravir (RLT) is a human immunodeficiency virus integrase strand transfer inhibitor that is prescribed for the treatment of HIV-1 infection. The drug belongs to biopharmaceutics classification system (BCS) class II category and has poor aqueous solubility and chemical stability in acidic/basic medium. Polymorph screening was performed to search for an alternative solid form with improved drug attributes. By serendipity, this screening gave anhydrous RLT (form A) and two crystalline solid phases of impurity C. The RLT form A and impurity C were characterised using powder X-ray diffraction (XRD), thermal analysis (differential scanning calorimetry/thermogravimetric analysis) and vibrational spectroscopy (Fourier-transform infrared). The crystal structures of form A and impurity C were determined from the high resolution powder XRD patterns using Rietveld refinement, thus revealing their conformational and synthon differences. The crystal structure of impurity C1 (MeOH solvate) was solved from single crystal XRD and demonstrates the packing and conformational differences compared to parent phase C. The dissolution/solubility experiments confirmed that form A has a higher solubility than its hydrate in aqueous ethanol medium. Compared to the commercialized RLT potassium salt (RLT-K), form A did not offer improved chemical stability during acid hydrolysis (high-performance liquid chromatography data). Rather, impurity C exhibited higher thermal stability and aqueous stability compared to other RLT solid forms in an acidic medium. [ABSTRACT FROM AUTHOR]

The relation between the ultrasonic characteristics and the ionic conductivity produced by Cu[sup +] and Ag[sup +] ions has been investigated in four-component CuGeAsS[sub 3] and AgGeAsSe[sub 3] chalcogenides. It is shown that the temperature range where ionic conductivity appears corresponds to the onset of a rapid decrease in the ultrasound velocity. [ABSTRACT FROM AUTHOR]

The 20th century started with the realization that working together and collaborating expedites new discoveries. The Solvay Conference in 1911 brought together scientists to try to understand the real nature of matter, the new elements, and their properties. Through global conflicts, the scientists stayed in communication and organized IUPAC and IUPAP to stay current in advances internationally in chemistry and physics, respectively. The outcomes include the discovery and naming of the elements that complete the periodic table of elements and the chart of nuclides with the heavy atoms and all of their isotopes. Mary Lowe Good forged new directions in developing tools in the field of radiochemistry. She exemplified cooperation and collaboration nationally and internationally. Now the advances in the heavy elements by Yuri Ts. Oganessian and colleagues staying close to the principles of international cooperation and sharing the new information about the connection of the production of super heavy elements to the main part of the chart of nuclides. The future lies in determining whether there are more elements to be discovered and what are their chemical properties. [ABSTRACT FROM AUTHOR]

Cephalexin (CPX) is a first-generation β-lactam antibiotic with great efficiency to kill Gram-positive and Gram-negative bacteria. Although the drug belongs to the BCS class I category of high solubility/permeability, it exhibits up to 20% degradation in acidic medium (pH 1.2). In order to improve its chemical stability, pharmaceutical cocrystal screening was carried out with a variety of ionizable/zwitterionic carboxylic acids and amino acids that resulted in a cocrystal with serine (SER), a cocrystal hydrate with 4-hydroxybenzoic acid (PHB) and a salt hydrate with 2,6-dihydroxybenzoic acid (DHB). A liquid-assisted grinding method was employed to obtain the multicomponent solid forms of CPX. The novel solid forms were characterized by powder X-ray diffraction (PXRD), FT-IR spectroscopy and thermal methods (DSC, TGA). The crystal structures of CPX–SER and CPX–DHB were solved in chiral space groups (P212121/P21) by powder XRD and single-crystal XRD techniques. Multiple functional groups in flexible CPX along with the coformer resulted in a complex hydrogen bonding network. The CPX–coformer heterosynthon is the key to forming multicomponent solids, although ionic interactions between the quaternary ammonium cation and the carboxylate ion of CPX are robust in all the solid forms. All the multicomponent solid forms were stable under 35 ± 5 °C and 75 ± 5% relative humidity conditions for a month. An aqueous stability experiment in 0.1 N HCl medium showed that the chemical stability of the novel multicomponent solids of CPX improved up to 2-fold compared to the commercial CPX monohydrate. [ABSTRACT FROM AUTHOR]

Estimates for energies of the -states are obtained proceeding from the existing correlation of the deformation energy and the lowest excitation energy. The considered systematics of energy ratios in the rotational band also makes it possible to obtain estimates for the and states. Comparison with results of other works has been carried out. [ABSTRACT FROM AUTHOR]

Dexamethasone (DEX) is a corticosteroid drug used to treat arthritis and asthma and considered a promising drug for the treatment of COVID-19. The major drawback of DEX is its poor aqueous solubility (89 mg L−1). In order to enhance its solubility, polymorph and cocrystal screening was performed, which resulted in the crystallization of the metastable polymorph (commercial Form A) along with two novel cocrystals with catechol (CAT) and resorcinol (RES). These solid forms were characterized by powder-XRD, DSC, and finally single-crystal XRD. The commercial Form A (P212121, Z′ = 1, new) and reported Form B (P212121, Z′ = 2) were harvested concomitantly during crystallization from CH3CN. While Form A constitutes a trimer ring motif, Form B maintains a dimer synthon between two symmetry independent DEX molecules and they are designated as synthon as well as packing polymorphs. The presence of CAT/RES breaks dimer/trimer synthons in the cocrystal lattice of the drug molecule and forms a hydrogen-bonded sandwich between two anti-parallel DEX chains. In addition, both DEX–CAT and DEX–RES are proved to be isostructural cocrystals based on their identical lattice parameters and molecular packing arrangement. Aqueous solubility (24 h) experiments indicated that commercial Form A was 1.5-fold more soluble than Form B and inversely correlated with their melting points. DEX–CAT and DEX–RES cocrystals improved the aqueous solubility by 2–5-fold than commercial Form A, although both the cocrystals transformed to the mixture of polymorphs during solubility experiments. The improved solubility of the DEX–CAT cocrystal may offer more bioavailability of DEX. [ABSTRACT FROM AUTHOR]

Titanosilicalite of the MFI type was obtained via a hydrothermal method. Its initial and annealed at 75 °C (TS-1P(75)) and 500 °C (TS-1P(500)) forms were studied by X-ray powder diffraction (PXRD), X-ray absorption spectroscopy (XAS-method), Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), temperature-programmed ammonia desorption (TPD NH3), and pyridine adsorption (Py). The full-profile Rietveld method allowed us to observe the presence of the organic template tetrapropylammonium hydroxide (TPAOH) in the framework voids, as well as to determine the silicate module (Si/Ti = 73.5) and the distribution of Ti4+ ions over the MFI-type structure sites (Ti atoms replace Si ones in two positions: T1 and T6). The coordination numbers of titanium (CNTi = 4.6 for TS-1P and TS-1P(75), CNTi = 3.8 for TS-1P(500)) were established by the XAS-method. The catalytic activity of titanosilicalites was found in the reactions of nitrous oxide decomposition (the maximal decomposition rate is demonstrated for the TS-1P(75) sample), allyl chloride epoxidation to epichlorohydrin (the best combination of all indicators was exhibited for the TS-1P sample) and propane conversion (maximum propane conversion, and butadiene and propylene selectivity were observed in both TS-1P(75) and TS-1P(500) samples). Mechanisms for the catalytic processes are proposed. The relationship between the catalytic properties and the composition (Si/Ti), Ti4+ ion distribution over the MFI-type structure sites, the local environment of titanium ions, and the number of acid sites in the titanosilicalites are discussed. [ABSTRACT FROM AUTHOR]

The rational design of metal–organic frameworks (MOFs) is highly important for the development of new proton conductors. Porphyrinylphosphonate-based MOFs, providing the directed tuning of physical and chemical properties of materials through the modification of a macrocycle, are potentially high-conducting systems. In this work the synthesis and characterization of novel anionic Zn-containing MOF based on palladium(II) meso-tetrakis(3-(phosphonatophenyl))porphyrinate, IPCE-2Pd, are reported. Moreover, the proton-conductive properties and structures of two anionic Zn-containing MOFs based on previously described nickel(II) and novel palladium(II) porphyrinylphosphonates, IPCE-2M (M = Ni(II) or Pd(II)), are compared in details. The high proton conductivity of 1.0 × 10−2 S cm−1 at 75 °C and 95% relative humidity (RH) is revealed for IPCE-2Ni, while IPCE-2Pd exhibits higher hydrolytic and thermal stability of the material (up to 420 °C) simultaneously maintaining a comparable value of conductivity (8.11 × 10−3 S cm−1 at 95 °C and 95% RH). The nature of the porphyrin metal center is responsible for the features of crystal structure of materials, obtained under identical reaction conditions. The structures of IPCE-2Pd and its dehydrated derivative IPCE-2Pd-HT are determined from the synchrotron powder diffraction data. The presence of phosphonic groups in compared materials IPCE-2M affords a high concentration of proton carriers that together with the sorption of water molecules leads to a high proton conductivity. [ABSTRACT FROM AUTHOR]

The new chiral metal-organic coordination polymer [ZnLH·4 H2O]n+/[HL]n− (H2L is 2-(l-prolylamino)benzene-1,4-dicarboxylic acid) was synthesized based on the available l-proline-substituted 2-aminobenzene-1,4-dicarboxylic acid derivative. The unique crystal structure of the new compound was established by powder X-ray diffraction. [ABSTRACT FROM AUTHOR]

An influence of hyper-hardening on structure and mechanical properties of ceramic solid solutions (SS) Li0.12Na0.88TayNb1–yO3 with tantalum concentrations у = 0.05; 0.25; 0.4 has been revealed. The researched was carried out using X-ray diffraction and scanning probe microscopy methods. Two ferroelectric phases co-exist in initial non-hardened SS Li0.12Na0.88TayNb1–yO3: hexagonal R3cH and rhombic P21ma. A symmetric rhombic phasePbnm prevails in hardened samples. Hyper-hardening has been established to sufficiently increase micro-hardness and surface strength of SSLi0.12Na0.88TayNb1–yO3ceramic samples. [ABSTRACT FROM AUTHOR]

Copper(I) halide and palladium(II) chloride complexes with tricyclic monastrol analogs containing the oxadiazocine ring have been synthesized and studied. The structures of the complexes were investigated with IR, NMR and UV spectroscopy. Two complexes, [Cu(L1)2Cl] and [Pd(L1)2Cl2], were structurally characterized by X-ray single-crystal and powder diffraction respectively. All the obtained coordination compounds were mononuclear. The ligands were coordinated with copper(I) and palladium(II) only via the soft sulfur atoms of thiocarbamide fragments, while the harder nitrogen and oxygen atoms remained uncoordinated. The palladium center was coordinated by two Cl ions and two S atoms from two 4-thioxo[1,3,5]oxadiazocine ligands in a distorted square-planar geometry. Copper(I) formed a trigonal planar geometry. The complexes demonstrated significant antibacterial activity towards the Escherichia coli K12 TG 1 bacterial strain in contrast to the free ligands, which didn't show any noticeable activity. [ABSTRACT FROM AUTHOR]

The creep strengthening mechanisms in (age‐hardenable) aluminum alloys are analyzed on the basis of a new microstructural study of powder samples, an analysis of a comprehensive revision of creep data from the literature, and a new modeling approach. A strategy based on the strength difference (SD) method to separate the contributions of solid solution atoms and precipitates to creep strengthening is proposed. The new methodology considers the combination of the two contributions avoiding the need of a threshold stress term in the creep equation. The contribution of both precipitates and solid solution is taken into account by means of the analysis of the lattice parameter variation with aging time. For this study, powders of two commercial AA2xxx alloys have been analyzed using diffraction methods. The experimental results are modeled using Lubarda's approach combined with the SD method. [ABSTRACT FROM AUTHOR]

A series of flexible metal–organic frameworks (MOFs) belonging to the MIL-53 family, such as MIL-53(Al), its amino-functionalized analog NH2-MIL-53(Al), and MIL-53(Al) type materials with Al3+ ions and mixed benzene-1,4-dicarboxylate and 2-aminobenzene-1,4-dicarboxylate linkers (MixLR) in various proportions were prepared in a nanocrystalline form using MW-activation under atmospheric pressure according to the original solvothermal procedure. The MIL-53(Al) and NH2-MIL-53(Al) samples feature nanocrystals with sizes of 200–300 nm, while MixLR matrices synthesized in this manner are composed of small nanoparticles with sizes of about 20–30 nm. MIL-53(Al) type materials (MIL-53(Al), NH2-MIL-53(Al) and MixLR) were probed in the adsorption of a typical herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in an aqueous medium. This study revealed a strong impact of the flexibility and porosity of the synthesized MIL-53(Al) type matrices on their physicochemical characteristics. MIL-53(Al) type materials show much higher 2,4-D adsorption rates than an activated carbon matrix (CSAC). The structural characteristics of the studied MIL-53(Al) type materials were established with a high resolution X-ray powder diffractometer equipped with a synchrotron radiation source. The obtained results can be used for the development of advanced adsorbents based on MIL-53(Al) type materials for water remediation. [ABSTRACT FROM AUTHOR]

Methods for detecting rare α-decays of heavy nuclei lately implemented at JINR's Flerov Laboratory of Nuclear Reactions (FLNR) are reviewed. Particular attention is paid to developing the active-correlation technique and various algorithms for real-time searches for correlated subprocesses in the nucleosynthesis of superheavy elements. These are required for suppressing the background events generated by the JINR heavy-ion cyclotron. A novel flexible approach to the search for correlated events based on a probabilistic algorithm is proposed. A simple criterion for optimizing the procedure of radical background suppression in full-fusion reactions is formulated. The implementation of the approaches proposed in this paper is motivated by the ever-increasing intensities of heavy-ion beams. [ABSTRACT FROM AUTHOR]

The meso‐imino derivatives of the palladium (II) and nickel (II) complexes of coproporphyrins I and II and β‐octaethylporphyrin were obtained by the Vilsmeier formylation followed by interaction with amines. The metal complexes of the azomethines obtained were transformed to the corresponding complexes of cyclopentane and cyclopentane‐pyrrolidone fused porphyrin derivatives by thermolysis. The plausible mechanism of such transformations was suggested and substantiated with quantum chemical calculations. Meso‐cyano‐, meso‐hydroxy‐, and meso‐aminocarbonyl derivatives of β‐octaethylporphyrin were obtained by treatment of the corresponding meso‐imino derivatives with bases. Demetalation of the nickel complex of the meso‐ hydroxy‐β‐octaethylporphyrin led to formation of the free base derivative. The structures of new types of the porphyrin derivatives were determined via X‐ray powder diffraction analysis. The obtained types of porphyrins are promising candidates to use as photosensitizers in medicine applications due to their longer wave absorption combined with high stability. New types of meso‐functionalization of porpyrins through formylation, Schiff base formation followed by thermal annulation or base treatment leading to cyclopentane‐condensed or meso‐cyano‐, meso‐amido‐, and meso‐hydroxy‐porphyrins. [ABSTRACT FROM AUTHOR]

Presents information on a study which analyzed temperature dependent ac conductivity of single-crystal proustite measured at several frequencies. Establishment of the ionic conduction mechanism in proustite; Prevention of the growth of silver dendrites at the electrodes; Results of the temperature variation of the ac conductivity; Frequency dependence of the ac conductivity.