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During Staphylococcus aureusinfections, reactive oxygen species cause DNA damage, including nucleotide base modification. After removal of the defective base, excision repair requires an endonuclease IV (Nfo), which hydrolyzes the phosphodiester bond 5′ to the abasic nucleotide. This class of enzymes, typified by the enzyme from Escherichia coli, contains a catalytic site with three metal ions, previously reported to be all Zn2+. The 1.05 Å structure of Nfo from the Gram-positive organism S. aureus(SaNfo) revealed two inner Fe2+ions and one Zn2+as confirmed by dispersive anomalous difference maps. SaNfo has a previously undescribed water molecule liganded to Fe1forming an octahedral coordination geometry and hydrogen bonded to Tyr33, an active site residue conserved in many Gram-positive bacteria, but which is Phe in Gram-negative species that coordinate Zn2+at the corresponding site. The 1.9 Å structure of E. coliNfo (EcNfo), purified without added metals, revealed that metal 2 is Fe2+and not Zn2+. Octahedral coordination for the sites occupied by Fe2+suggests a stereoselective mechanism for differentiating between Fe2+and Zn2+in this enzyme class. Kinetics and an inhibitor competition assay of SaNfo reveal product inhibition (or slow product release), especially at low ionic strength, caused in part by a Lys-rich DNA binding loop present in SaNfo and Gram-positive species but not in EcNfo. Biological significance of the slow product release is discussed. Catalytic activity in vitro is optimal at 300 mM NaCl, which is consistent with the halotolerant phenotype of S. aureus.

A comprehensive theoretical investigation into the gold-catalyzed synthesis of polysubstituted pyrazolines and dihydropyridines from imines and methyl phenylpropiolate was conducted in this study. Three imines with distinct substituents were selected as model reactants. The computational outcomes reveal that four-membered intermediates generated from aza-enyne metathesis significantly affect the reaction selectivity. For nitrogen-centered NHCO2Me substituents (series A), an outward ring opening occurs during the metathesis of the aza-alkyne. This leads to the formation of Z-butadiene intermediates and ultimately to pyrazoline products. Conversely, with an aromatic substituent at the nitrogen site (series Band C), an inward ring opening takes place. This results in E-butadiene intermediates and the synthesis of dihydropyridine derivatives. The dihydropyridine product’s configuration is determined by the aromatic ring’s substituent. Electron-donating groups tend to directly form 1,4-dihydropyridine through a 6π electrocyclization (series B). In contrast, strong electron-withdrawing substituents initially undergo azayne metathesis, followed by 6π electrocyclization to produce 1,2-dihydropyridine products (series C). Furthermore, the distinctive selectivities were investigated in depth using global reactivity index and distortion/interaction methods. This research may contribute to the design of more effective and selective protocols to access pyrazolines, dihydropyridines, and related compounds.

An aromatic tricarboxylic acid building block, [1,1′:3′,1″-terphenyl]-4,4″,5′-tricarboxylic acid (H3tptca), was used as a versatile linker for assembling, under hydrothermal conditions, a series of 12 new coordination polymers (CPs) in the presence of supporting N-donor ligands acting as mediators of crystallization. The obtained products were formulated as [Mn(μ-Htptca)(phen)2]n·nH2O (1), [Zn(μ-Htptca)(2,2′-bipy)(H2O)]n·nH2O (2), [Ni(μ3-Htptca)(μ-4,4′-bipy)]n·2nH2O (3), [Co(μ3-Htptca)(μ-bpe)]n(4), [M3(μ3-tptca)2(phen)3(H2O)2]n·2nH2O (M = Co (5), Zn (6)), [Co2(μ4-tptca)(μ-OH)(2,2′-bipy)2]n(7), [Zn3(μ3-tptca)2(2,2′-bipy)3(H2O)2]n·4nH2O (8), {[Cd(H2biim)3][Cd2(μ3-tptca)(μ5-tptca)]}n(9), [Co2(μ4-tptca)(μ-bpa)(μ3-OH)(H2O)2]n·nH2O (10), [Ni3(μ3-tptca)2(μ-bpa)3(H2O)4]n·5nH2O (11), and [Co2(μ4-tptca)(μ-bpb)(μ-OH)]n(12), wherein phen, 2,2′-bipy, 4,4′-bipy, bpe, H2biim, bpa, and bpb are 1,10-phenanthroline, 2,2′- and 4,4′-bipyridine, 1,2-di(4-pyridyl)ethane, 2,2′-biimidazole, bis(4-pyridyl)amine, and 1,4-bis(pyrid-4-yl)benzene, respectively. Crystal structures of CPs 1–12reveal a broad diversity metal–organic networks that range from 1D chains (1, 2, 5, 6, and 8) to 2D layers (3, 4, 7, 9, and 11) and 3D nets (10and 12), including the examples of interpenetrated, polycatenated, and topologically unique architectures. Structural features and catalytic properties of the obtained CPs were studied and discussed. In particular, a Zn(II) CP 8acts as an efficient and recyclable heterogeneous catalyst for the mild cyanosilylation of benzaldehydes, leading to the formation of the corresponding cyanohydrin products in up to 99% yields. The obtained compounds widen a growing family of functional CPs driven by terphenyl-tricarboxylate linkers.

We report a high nuclear (Cu14) complex synthesized via the self-assembly of copper-methylsilsesquioxane induced by the complexation with 1,2-bis(diphenylphosphino)ethane (dppe). The structure includes two cationic CuI(dppe)2moieties and an anionic silsesquioxane cage of an unprecedented CuII12structural type. The Cu12cage fragment exhibits a unique (i) combination of Si4-cyclic/Si2-acyclic silsesquioxane ligands and (ii) encapsulation of two different chloride and carbonate species. This complex acts as a promising precatalyst in the mild oxidation and carboxylation of light alkanes to produce alkyl hydroperoxides, alcohols, ketones, or carboxylic acids. The present study widens the family of copper-methylsilsesquioxane clusters with prospective use in oxidation catalysis.

Abstract: Synthesis of highly porous ceramic materials for catalytic converters based on coarse-dispersed αAl2O3using a combination of compaction and thermochemical synthesis with the participation of active ultrafine binders is carried out. Using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM), it is established that the morphology of the synthesized material simultaneously includes large pores between filler particles (dominant αAl2O3phase) and submicron pores in transboundary regions that appeared during the processes of liquid-phase sintering and gas evolution. A significant amount of indialite (Mg2Al4Si5O18) and spinel (MgAl2O4) formed as a result of thermochemical synthesis on surfaces and in the gaps between coarse-dispersed particles is revealed. The dominant pore size (according to the volume of mercury intrusion) is from 20 to 60 μm (about 73%), as well as pores with size from 0.4 to 2 μm (about 6%).The average pore size is about 9 μm. Highly porous materials with these characteristics of the pore space can be effectively used after modification as catalytic converters for the dehydrogenation of alkyl aromatic hydrocarbons with large molecular sizes (about 400 nm) with a long mean free path on the order of ~3–4 μm.

Two heterometallic cyanometallate-driven Cu(II)/Co(III) coordination polymers, [{Cu2K(H2tipa)2(H2O)4}Co(CN)6]n·4nH2O (1) and [{Cu2(H2tea)2}3{Co(CN)6}2]n·10nH2O (2), were self-assembled from Cu(NO3)2, an aminoalcohol chelator (H3tipa, triisopropanolamine; or H3tea, triethanolamine), and K3[Co(CN)6]. The compounds were fully characterized by single-crystal and powder X-ray diffraction, FTIR spectroscopy, and thermogravimetric and elemental analyses, revealing 1D (1) and 2D (2) metal–organic architectures with 2C1 and hcbtopologies constructed from [Cu2K(H2tipa)2(H2O)2]3+or [Cu2(H2tea)2]2+blocks and [Co(CN)6]3–linkers. A detailed magnetic study of 1and 2was performed by variable-temperature magnetic susceptibility measurements and broken symmetry DFT calculations. These new compounds expand a family of heterometallic coordination polymers derived from hexacyanocobaltate(III) linkers, with compound 1also representing the first structurally characterized heterotrimetallic Cu/Co/K derivative.

The urea oxidation reaction (UOR) is an alternative anodic reaction for hydrogen generation via water splitting. The significance of UOR lies in both H2production and the decontamination of urea-containing wastewater. Commercial electrocatalysts in this field are generally based on noble metals and show several limitations. Bimetal–organic frameworks (BMOFs) can be excellent candidates for the replacement of noble-metal-based catalysts beacuse of their promising features, such as a tunable structure, high surface area, and abundant sites for electrocatalysis. In this study, a series of nickel–cobalt BMOFs (Nix-Coy-BMOFs: xand yrefer to a molar fraction of Ni and Co) were synthesized and applied as electrocatalysts in UOR. In particular, a Ni0.15Co0.85-MOF material with a structure similar to that of its parent Co-MOF, revealed exceptional electrocatalytic performance, as evidenced by low values of overpotential (1.33 V vs RHE at 10 mA cm–2), TOF (0.47 s–1), and Tafel slope (125 mV dec–1). At a 40 mA cm–2current density, Ni0.15Co0.85-MOF also showed excellent stability during the 72 h tests. This performance of NiCo-BMOF can be assigned to the synergistic effect between Co and Ni, abundant active sites, porosity, and a tunable structure, all of which result in an increased reaction rate due to the acceleration of charge and mass transfers. Thus, the present work introduces an efficient noble-metal-free UOR for energy generation from urea-based wastewater.

Alkane elimination reactions between the diamino- and dianilino-bridged tetrakis(phenolate) proligands 1a,b-H4and precursors M(CH2SiMe3)3(THF)2, M(CH2C6H4-o-NMe2)3(M = Sc and Y), and Hf(CH2Ph)4were investigated. The diamino-bridged 1a-H4afforded nonsymmetric complex 2a-Y2incorporating two metal centers in different coordination environments. This one and other dinuclear compounds 2b-Sc2, 2a-Hf2, and 2b-Hf2were characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction study (for 2a-Y2and 2b-Sc2) and turned out to be symmetric in solution. Compound 2a-Y2, upon treatment with 2 equiv of 2-phenylpyridine, afforded symmetric bis(aryl) product 3a-Y2, which was authenticated by NMR spectroscopy and X-ray crystallography. The mechanism of its formation was studied by DFT computations and presumably involves a cooperative reorganization process within the nonsymmetric parent 2a-Y2to afford a symmetric isomer prior to its reaction with 2-phenylpyridine.

The mechanisms and regio-, chemo-, and stereoselectivity were theoretically investigated in the Rh(III)-catalyzed [5 + 1] annulation of 2-alkenylanilides and 2-alkylphenols with allenyl acetates. Two different reactants, 2-alkenylanilides and 2-alkylphenols, were selected as model systems in the density functional theory calculations. The obtained theoretical results show that both these reactants exhibit similar steps, namely, (1) N–H/O–H deprotonation and C–H activation, (2) allenyl acetate migratory insertion, (3) β-oxygen elimination, (4) intramolecular nucleophilic addition of the nitrogen/oxygen–rhodium bond resulting in [5 + 1]-annulation, and (5) protonation with the formation of the desired product and regeneration of the Rh(III) catalyst. The theoretical evidence suggests that the selectivity is determined at the step of allenyl acetate’s migratory insertion. Moreover, the regioselectivity is driven by electronic effects, while the interaction energies (C–H···π and C–H···O interactions) play a more imperative role in controlling the stereoselectivity. The obtained theoretical results not only well rationalize the experimental observations but also provide important mechanistic insights for related types of [5 + 1]-annulation reactions.

Two heterometallic Cu(II)/Ni(II) coordination polymers, [Cu2(Hbdea)2Ni(CN)4]n(1) and [Cu2(dmea)2Ni(CN)4]n·nH2O (2), were successfully self-assembled in water by reacting Cu(II) nitrate with H2bdea (N-butyldiethanolamine) and Hdmea (N,N-dimethylethanolamine) in the presence of sodium hydroxide and [Ni(CN)4]2–. These new coordination polymers were investigated by single-crystal and powder X-ray diffraction and fully characterized by FT-IR spectroscopy, thermogravimetry, elemental analysis, variable-temperature magnetic susceptibility measurements, and theoretical DFT and CASSCF calculations. Despite differences in crystal systems, in both compounds, each dinuclear building block [Cu2(μ-aminopolyalcoholate)2]2+is bridged by diamagnetic [Ni(CN)4]2–linkers, resulting in 1D (1) or 2D (2) metal–organic architectures. Experimental magnetic studies show that both compounds display strong antiferromagnetic coupling (J= −602.1 cm–1for 1and −151 cm–1for 2) between Cu(II) ions within the dimers mediated by the μ-O-alkoxo bridges. These results are corroborated by the broken symmetry DFT studies, which also provide further insight into the electronic structures of copper dimeric units. By reporting a facile self-assembly synthetic protocol, this study can be a model to widen a still limited family of heterometallic Cu/Ni coordination polymer materials with different functional properties.

The development of sustainable biomaterials and surfaces to prevent the accumulation and proliferation of viruses and bacteria is highly demanded in healthcare areas. This study describes the assembly and full characterization of two new bioactive silver(I) coordination polymers (CPs) formulated as [Ag(aca)(μ-PTA)]n·5nH2O (1) and [Ag2(μ-ada)(μ3-PTA)2]n·4nH2O (2). These products were generated by exploiting a heteroleptic approach based on the use of two different adamantoid building blocks, namely 1,3,5-triaza-7-phosphaadamantane (PTA) and 1-adamantanecarboxylic (Haca) or 1,3-adamantanedicarboxylic (H2ada) acids, resulting in the assembly of 1D (1) and 3D (2). Antiviral, antibacterial, and antifungal properties of the obtained compounds were investigated in detail, followed by their incorporation as bioactive dopants (1 wt %) into hybrid biopolymers based on acid-hydrolyzed starch polymer (AHSP). The resulting materials, formulated as 1@AHSP and 2@AHSP, also featured (i) an exceptional antiviral activity against herpes simplex virus type 1 and human adenovirus (HAd-5) and (ii) a remarkable antibacterial activity against Gram-negative bacteria. Docking experiments, interaction with human serum albumin, mass spectrometry, and antioxidation studies provided insights into the mechanism of antimicrobial action. By reporting these new silver CPs driven by adamantoid building blocks and the derived starch-based materials, this study endows a facile approach to access biopolymers and interfaces capable of preventing and reducing the proliferation of a broad spectrum of different microorganisms, including bacteria, fungi, and viruses.

The mechanism, regioselectivity, chemoselectivity, and the effects of substituents were explored using density functional theory (DFT) in the oxidative functionalization of yndiamides catalysed by gold(i) [IPrAuNTf2] or Brønsted acid (HNTf2) systems. The calculations revealed that both catalysts entail a similar type of nucleophilic attack on the catalyst-ligated yndiamide, forming a vinyl intermediate that can isomerize to gold carbene or carbocation upon the cleavage of the N–O bond. Next, the gold carbene or carbocation is easily captured by external nucleophilic reagents and finally desaturated viaa proton shift, assisted by a substrate or NTf2−to yield the final product. The unique features of regio- and chemoselectivity were explored in detail through distortion/interaction and global reactivity index (GRI) analyses. The effects of substituents in yndiamides were also investigated. Apart from completely rationalizing the experimental data and intricate selectivity patterns, the obtained theoretical evidence can provide a significant contribution toward understanding the resembling types of reaction mechanisms.

The mechanism, enantioselectivity, and effect of chiral phosphoric acid (CPA) cocatalyst were investigated by the density functional theory (DFT) for the three-component asymmetric aminohydroxylation between two diazo compounds and a hydroxylamine derivative. This type of cascade process is cooperatively catalyzed by Rh2(OAc)4and CPA. The obtained results clearly indicate that the first step of the global reaction involves a nucleophilic attack at the nitrogen center of N-hydroxyaniline by rhodium–carbene intermediates producing imines. Subsequently, an enolate intermediate was recognized as the key species generated from the second diazo compound and the leaving benzyl alcohol (BnOH) fragment of the first step and in the presence of the same dirhodium catalyst. Then, the reaction is terminated by the asymmetric Mannich-type addition, delivering the aminohydroxylation products of an S-Rconformation with the assistance of chiral phosphoric acid. The distortion/interaction analysis shows that the relative distortions of CPA and the enol play a vital role in the energy ordering of the stereocontrolling transition states (TSs). Furthermore, the influence of different substituents in CPA was fully rationalized by distortion/interaction analysis. This study opens up novel synthetic possibilities and improves the reaction predictability when exploring the related types of cooperatively catalyzed organic transformations.

Abstract—: The objective of the article is to assess the scale and dynamics of shrinkage of cities in Russia and its regions in the post-Soviet period. Urban shrinkage analysis, based on the average annual index of population decrease according to population censuses, showed that these processes (at least during one of the intercensal periods) in total covered more than half of Russian cities. At the same time, in less than a third of centers, the average annual population decrease over the entire period exceeded 1%. In 1989–2002, the number of shrinking cities was quite small (less than a quarter), and during subsequent intercensal periods, it increased significantly, amounting to more than a third of all cities in the country by 2021. Analysis of the spatial distribution of urban shrinkage showed that these processes occurred at different stages, both at the expense of the resource cities in the northern and eastern territories of the country, and centers of old-developed regions, primarily the Non-Chernozem zone. Most shrinking cities are represented by small centers with populations of less than 50 000 people. With the general negative nature of population dynamics, there is a multidirectionality and variability of shrinkage trends in Russian cities. The specific features of shrinkage during each of the three intercensal periods and alternating phases of depopulation formed the basis for distinguishing six types of urban shrinkage trajectories.

Ten copper-based cage silsesquioxanes were prepared via convenient self-assembly synthesis employing halides of different quaternary ammonium cations, namely, Me4NBr, Et4NBr, PhMe3NCl, BzMe3NCl, and BzEt3NCl. This approach led to cages of similar Cu4M2nuclearity (M = Rb, K, or Na). Sandwich-like structures of all compounds were established by single-crystal X-ray diffraction studies using synchrotron radiation. In all products, anionic cages are based on two cyclic silsesquioxane [Ph6Si6O12] ligands, coordinating to a central hexagonal CuII4M2motif with a 2M6-1 topology. The complexes include two charge balancers, namely, quaternary N-cations located at the external (crown ether-like) positions to cage fragments. Selected compounds were tested as homogeneous multicopper(II) catalysts in a series of model reactions, such as the mild oxidation and carboxylation of alkanes, including inert gaseous C2–C4saturated hydrocarbons. This study extends the types of synthetic approaches and family of ionic metallasilsesquioxanes with promising structural features and catalytic properties.

Background: The impact of environmental drivers of biodiversity change on the native vegetation of Kazakhstan is so far poorly understood. Aims: To compare historical and contemporary data on the floristic composition of plant communities with Aflatunia ulmifolia against the backdrop of sixty years of climate and land-use change. Methods: In 2021–2022, we revisited a river gorge in the Dzhungarskiy Alatau that had been originally surveyed in 1962. We estimated floristic composition and abundance of species on the Drude scale, and evaluated floristic similarity and abundance change between our dataset and that of 1962. Results: In total, 226 species belonging to 166 genera and 52 families were recorded. The vast majority were native, and only 8 species were exotic. Historical surveys recorded 104 species, and recent surveys, 199 species, the surveys from the two observation periods sharing only 77 species. The Sörensen similarity coefficient was the highest for native shrubs (0.8), and the lowest for native herbaceous plants (0.46). The increase in floristic diversity was largely due to the increase in the number of herbaceous species, mostly perennial forbs. Conclusions: The observed changes could be a result of increased frequency of shallow landslides, grazing exclusion, and growing human presence. Taxonomic references: Flora of Kazakhstan (1956–1966), Identification Guide to the Plants of Middle Asia (1968–1993), S.A. Abdulina (1999), International Plant Names Index (IPNI 2022) for vascular plants.

The present work focuses on the synthesis and properties of a novel multifunctional cerium(III) MOF, [Ce2(data)3(DMF)4]·DMF (data2–: 2,5-diaminoterephthalate), abbreviated as NH2-Ce-MUM-2. Its crystal structure reveals an intricate 3D 4,5-connected framework with a xahtopology. This MOF features unique properties, such as open metal sites, presence of free amino groups, and high stability. Two main applications of NH2-Ce-MUM-2 were investigated: (i) as a heterogeneous catalyst in the CO2fixation into cyclic carbonates and (ii) as a material with third-order nonlinear optical activity. As a model reaction, the cycloaddition of CO2to propylene oxide to give the corresponding cyclic carbonate was explored under mild conditions, at the atmospheric pressure of carbon dioxide and in the absence of cocatalyst and added solvent. Various reaction parameters were investigated toward optimization and exploration of substrate scope, revealing up to 99% product yields of cyclic carbonate products. Besides, the structure of NH2-Ce-MUM-2 is highly stable, permitting its recyclability and reusability in further catalytic experiments. The significant contributions of free amino groups and open metal sites within this catalyst were particularly considered when proposing a potential mechanism for the reaction. Z-Scan measurements were used to evaluate the nonlinear optical (NLO) properties of NH2-Ce-MUM-2 at various laser intensities. A high two-photon absorption (TPA) under greater incident intensities shows that NH2-Ce-MUM-2 might be applicable in optical switching devices. Besides, the self-focusing effects of NH2-Ce-MUM-2 under various incident intensities were highlighted by the nonlinear index of refraction (n2). By reporting the synthesis and characterization of a novel MOF, along with its highly promising catalytic and NLO behavior, the current study introduces an additional example of multifunctional material into a growing family of metal–organic frameworks.

To prevent negative effects of smoking, there is constant research on the development of various types of sustainable filter materials, capable of removing toxic compounds present in cigarette smoke. Because of the extraordinary porosity and adsorption properties, metal–organic frameworks (MOFs) represent promising adsorbents for volatile toxic molecules such as nicotine. This study reports new hybrid materials wherein six types of common MOFs of different porosity and particle size are incorporated into sustainable cellulose fiber from bamboo pulp, resulting in a series of cellulose filter samples abbreviated as MOF@CF. The obtained hybrid cellulose filters were fully characterized and investigated in nicotine adsorption from cigarette smoke, using a specially designed experimental setup. The results revealed that the UiO-66@CF material features the best mechanical performance, facile recyclability, and excellent nicotine adsorption efficiency that attains 90% with relative standard deviations lower than 8.80%. This phenomenon may be caused by the large pore size, open metal sites, and high loading of UiO-66 in cellulose filters. Additionally, the high adsorption capacity showed almost 85% removal of nicotine after the third adsorption cycle. The DFT calculation methods allowed further investigation of the nicotine adsorption mechanism, showing that the energy difference between HOMO and LUMO for UiO-66 was the closest to that of nicotine, which further proves the adsorption ability of nicotine by this material. Owing to the flexibility, recyclability, and excellent adsorption performance, the prepared hybrid MOF@CF materials may find prospective applications in nicotine adsorption from cigarette smoke.

The aim of this research is to assess the current status, potential and problems of human resources for forestry in municipal state forest management institutions (MSFMIs) of Kazakhstan. A total of 120 MSFMIs are functional in Kazakhstan, with almost 5.5 thousand employees, of which 6.1% are women. Overall 63% are foresters, 13% are masters of the wood, 13% are engineers of forestry of all categories, 7% are forest wardens and 4% are directors. The quality of education of forest workers also varies and a minority of forest workers has a higher education. The scenario also suggested that almost 3000 specialists had taken up the advanced training courses from 2003 to 2019. According to a survey of employees of the MSFMIs of two pilot oblasts (Almaty and East Kazakhstan), the average age of an employee is 44.7 years and 79.2% of employees have a work experience of up to 15 years. The main issues and difficulties observed in the work of MSFMIs staff were low wages, lack of modern technique and equipment for forest service, lack of systematic continuing education of employees, poor quality of education, as well as staff turnover, especially foresters, which consequently affects their professional level.

4,4′-(Pyridine-3,5-diyl)dibenzoic acid (H2pdba) was explored as an adaptable linker for assembling a diversity of new manganese(II), cobalt(II/III), nickel(II), and copper(II) coordination polymers (CPs): [Mn(μ4-pdba)(H2O)]n(1), {[M(μ3-pdba)(phen)]·2H2O}n(M = Co (2), Ni (3)), {[Cu2(μ3-pdba)2(bipy)]·2H2O}n(4), {[Co(μ3-pdba)(bipy)]·2H2O}n(5), [Co2(μ3-pdba)(μ-Hbiim)2(Hbiim)]n(6), and [M(μ4-pdba)(py)]n(M = Co (7), Ni (8)). The CPs were hydrothermally synthesized using metal(II) chloride precursors, H2pdba, and different coligands functioning as crystallization mediators (phen: 1,10-phenanthroline; bipy: 2,2′-bipyridine, H2biim: 2,2′-biimidazole; py: pyridine). Structural networks of 1–8range from two-dimensional (2D) metal–organic layers (1–3, 5–8) to three-dimensional (3D) metal–organic framework (MOF) (4) and disclose several types of topologies: sql(in 1), hcb(in 2, 3, 5), tfk(in 4), 3,5L66 (in 6), and SP 2-periodic net (6,3)Ia (in 7, 8). Apart from the characterization by standard methods, catalytic potential of the obtained CPs was also screened in the Knoevenagel condensation of benzaldehyde with propanedinitrile to give 2-benzylidenemalononitrile (model reaction). Several reaction parameters were optimized, and the substrate scope was explored, revealing the best catalytic performance for a 3D MOF 4. This catalyst is recyclable and can lead to substituted dinitrile products in up to 99% product yields. The present study widens the use of H2pdba as a still poorly studied linker toward designing novel functional coordination polymers.

Let λbe a partition of an integer nand Fqbe a finite field of order q. Let Pλ(q)be the number of strictly upper triangular n×nmatrices of the Jordan type λ. It is known that the polynomial Pλhas a tendency to be divisible by high powers of qand Q=q-1, and we put Pλ(q)=qd(λ)Qe(λ)Rλ(q), where Rλ(0)≠0and Rλ(1)≠0. In this article, we study the polynomials Pλ(q)and Rλ(q). Our main results: an explicit formula for d(λ)(an explicit formula for e(λ)is known, see Proposition 3.3 below), a recursive formula for Rλ(q)(a similar formula for Pλ(q)is known, see Proposition 3.1 below), the stabilization of Rλwith respect to extending λby adding strings of 1’s, and an explicit formula for the limit series Rλ1∞. Our studies are motivated by projected applications to the orbit method in the representation theory of nilpotent algebraic groups over finite fields.

Abstract: A porous ceramic catalytic converter was synthesized on the basis of a coarse α-Al2O3powder filler using ultrafine strengthening binders of the MgO + SiC + SiO2composition and catalytically active Re2O7and WO3components (up to 4 wt %). Double-sided compression of the starting mixture under a pressure from 70 to 90 MPa followed by sintering of the samples at temperatures from 1200 to 1400°C was applied. The synthesized ceramic catalytic converters possessed an open porosity of about 40% and a pore size of 0.5 to 1.5 μm. The styrene selectivity of about 30% and the productivity up to 30 g h–1dm–3in the temperature range from 600 to 700°С were experimentally achieved. The degree of catalyst carbonization within the experimental time (6 h) did not exceed 0.31 wt %. The scientific principles of a one-step technology for the synthesis of a porous ceramic with simultaneous imparting of catalytic properties thereto were developed. The obtained ceramic catalytic converters of the [Re,W]/α-Al2O3composition can produce styrene with a high efficiency in a wide temperature range.

With global sales of $5 billion in 2007, baby care (which, defined by Euromonitor International, includes cosmetics and toiletries products for children 11 and under) remains one of the smallest [...]

The global cosmetics and toiletries industry saw another year of strong growth in 2007 to reach a value of $290.9 billion. According to Euromonitor International's research, the market grew by [...]

ABSTRACTEuonymus verrucosusScop. (Celastraceae) is a boreal European-Mediterranean-Asia Minor forest relict species and is listed in the Red Data Books of Kazakhstan and some regions of the Russian Federation. Thus, in the present study, in vitroregeneration of E. verrucosusutilizing young shoot explants was attempted for the first time. Initially, the young shoots (0.8–1.0 cm length) were placed in woody plant medium (WPM) and Murashige and Skoog’s (MS) medium fortified with different concentrations of cytokinins, such as 6-benzylaminopurine (BAP), kinetin (Kn) and thidiazuron (TDZ), to induce axillary buds. The optimum induction was 75.0 ± 2.9% and the apical growth was 3.74 ± 0.06 cm for young shoots after 4 weeks in WPM medium supplemented with BAP (1.0 mg L−1). Simultaneously, during the formation of axillary shoots, callus induction was observed at the nodal base. Subculturing this callus on fresh medium every 4 weeks generated total six adventitious shoots with 0.70 ± 0.02 cm length after 12 weeks in the presence of BAP (1.0 mg L−1). When the adventitious shoots were isolated and transferred again to WPM medium containing 2.0 mg L−1Kn, 2.95 ± 0.16 shoots were formed with 51.2% regeneration frequency within 4 weeks. These microshoots were then rooted ex vitroand an optimum 73.3% rooting was achieved within 4 weeks in a substrate highbog peat with a 0.5 cm layer of vermiculite. This micropropagation protocol will be helpful for the conservation of the genetic resources and biodiversity for E. verrucosus.

This study describes the preparation, characterization, and antimicrobial properties of novel hybrid biopolymer materials doped with bioactive silver(I) coordination polymers (bioCPs). Two new bioCPs, [Ag2(μ6-hfa)]n(1) and [Ag2(μ4-nda)(H2O)2]n(2), were assembled from Ag2O and homophthalic (H2hfa) or 2,6-naphthalenedicarboxylic (H2nda) acids as unexplored building blocks. Their structures feature 2D metal–organic and supramolecular networks with 3,6L64 or sql topology. Both compounds act as active antimicrobial agents for producing bioCP-doped biopolymer films based on epoxidized soybean oil acrylate (SBO) or potato starch (PS) as model biopolymer materials with a different rate of degradability and silver release. BioCPs and their hybrid biopolymer films (1@[SBO]n, 2@[SBO]n, 1@[PS]n, and 2@[PS]n) with a very low loading of coordination polymer (0.05–0.5 wt %) show remarkable antimicrobial activity against Staphylococcus aureusand Staphylococcus epidermidis(Gram-positive) and Escherichia coliand Pseudomonas aeruginosa(Gram-negative) bacteria. Biopolymer films also effectively impair the formation of bacterial biofilms, allowing total biofilm inhibition in several cases. By reporting on new bioCPs and biopolymer films obtained from renewable biofeedstocks (soybean oil and PS), this study blends highly important research directions and widens a limited antimicrobial application of bioCPs and derived functional materials. This research thus opens up the perspectives for designing hybrid biopolymer films with outstanding bioactivity against bacterial biofilms.

The present work focuses on a theoretical investigation of mechanistic features, chemoselectivity, regioselectivity, and effect of substituents in the gold-catalyzed reactions of alkynyl thioethers and isoxazoles. The DFT calculations reveal that the nucleophilic attack of isoxazole to a β-position of catalyst-bound ynamide forms a vinyl intermediate. This undergoes cleavage of the N–O isoxazole bond and isomerizes to form an α-imino α′-sulfenyl gold carbene complex with stabilization of the Au–S interaction. For 3,5-dimethylisoxazole, the reaction follows a formal [3 + 2] cycloaddition pathway and a 1,3-H migration to give the pyrrole products. Replacement of 3,5-dimethylisoxazole by 3,5-dimethyl-4-phenylisoxazole leads to the formation of deacylative annulation products and desulfenylated 3-acylated pyrroles. Reactions with 4-methyl-3,5-diphenylisoxazoles induce the formation of N-acylated pyrroles and desulfenylated 3-acylated pyrroles. For the minor pathway, the α-addition and 1,2-S migration result in sulfur-substituted β-keto enamide derivatives. In addition, the unique features of regio- and chemoselectivity were rationalized by the distortion and interaction analysis. Apart from fully rationalizing the experimental results, the theoretical DFT data give an important support for comprehending related types of reaction mechanisms.

Within the sweeping research on the design of new coordination polymers and related metal–organic architectures, the use of silsesquioxane derivatives as important organosilicon building blocks has been poorly explored, despite a number of unique structural and functional characteristics of the resulting products. The present study thus describes an extended series (eight examples) of heterometallic Cu4Cs4and Cu4Rb4coordination polymers with the common formula [(PhSiO1.5)12(CuO)4(AO0.5)4(Solv)x]n·nSolv (A is Cs or Rb; Solv refers to ligands and/or solvate molecules including H2O, EtOH, BuOH, DMF, and DMSO in various combinations), which are based on cagelike coppersilsesquioxanes as nontrivial secondary building units. The concept of supramolecular design was implemented in a straightforward way by the assembly of coppersilsesquioxane cages using large and coordination-versatile cesium or rubidium cations. The structures of all products were established by single-crystal X-ray diffraction studies mainly using synchrotron radiation. The resulting Cu4Cs4- and Cu4Rb4-silsesquioxanes exhibit an extracage location of the alkali-metal cations, which enables the interconnectivity of neighboring cages into 1D, 2D, or 3D coordination polymer architectures. The unique feature of such architectures is a realization of metallocene Cs···π (Rb···π) joints, providing tightly connected nonporous coordination polymers. A topological classification of cages and coordination polymer networks was performed. Some of the obtained compounds also represent the first examples of Rb-containing silsesquioxanes. The selected products were also tested as homogeneous catalysts in the oxidation and hydrocarboxylation of C5–C8cycloalkanes. This study extends the structural types of heterometallic silsesquioxane cages that can be efficiently applied to the design of functional coordination polymers.

In Russian educational practice, there are not many studies devoted to the approach of linguistic discourse of gifted students’ education from a historical point of view. The study considers giftedness as a complex system of abilities and analyzes approaches to the study of giftedness in accordance with the teaching of linguistic disciplines. Linguistics as a discipline studies various aspects of language and is closely related to the system of sciences, the study of which is necessary for the formation of students’ giftedness and the level of their worldview. In the course of the study, both qualitative (the dynamics of changes in the proportion of students participating in additional educational programs for children in 2015–19 in relation to their total number) and quantitative (the dynamics of changes in the total number of students participating in additional educational programs for children in 2015–19 and thoroughly studying certain areas in 2019) were collected. The information was collected in the course of the research using content search in open educational databases of Moscow and the Moscow region. The results of the study show that the availability of various types of modern educational technologies increases the pedagogical capabilities of teachers to develop the abilities and talents of children, as well as contributes to the efficient knowledge assimilation and broadens the horizons of learners. The practical use of the research results involves the exchange of the experience related to the application of additional methods to study linguistics, history and social studies.

Abstract—: The paper summarizes recent studies by Russian researchers on various types of temporary mobility and related population pulsations. It is shown that the practice of their study in Russia is in line with the key areas of research on the spatiotemporal population dynamics currently developing abroad. The methodology of work commuting studies is enriched, the first research studies on the event-related mobilities tend to appear. Forms of mobility specific to Russia are also being actively studied, including dacha migration (in many respects close to migration to second homes widespread abroad) and otkhodnichestvo. In addition to objective trends associated with the growth of population mobility, the rapid growth of research interest stems from the expansion of information and the resource base on temporary mobility, including agricultural census materials, mobile network operators’ data, interpretation of satellite images, etc. The review of certain types of mobility provides estimates of the scale of their distribution in Russia, intensity, and rhythmic patterns and summarizes key factors (spatial, social, labor, etc.). The content of the approaches used by Russian authors is revealed, the results obtained by referring to special methods of seasonal mobility and the mechanisms of its dynamics are given. The main directions, methodological barriers, and challenges of future studies of mobility and pulsations, including the need to research territories with the greatest intensity of temporary mobility, have been identified. The potential for using methods to analyze temporal population pulsations in relation to the spatiotemporal variability of settlement systems is shown. In particular, the case of the Moscow metropolitan region demonstrates the basic laws of polyrhythmic pulsation mechanisms, leading to maximum variability (involving up to 40% of the permanent population). The theory of population pulsations is at the formation stage: despite the development of the first models of pulsating settlement systems, including the pulsating urban agglomeration model, many of their quantitative parameters still remain infor-mal.

This study describes the self-assembled synthesis, characterization, and structural features of two new heterometallic Fe6Ln clusters, [Fe6Ln(μ3-OH)2(mdea)6(N3)6(NO3)] (Ln = Y (1), Gd (2); mdeaH2= N-methyldiethanolamine). The obtained compounds possess a unique crystalline structure with a vertex-sharing butterfly-like Fe3LnFe3motif and a rare type of 2,3,4M7-1 topology. The compounds show a new prototype structure with a distinctive arrangement of a lanthanide center between the Fe3triangles. Magnetic properties of the obtained clusters were investigated in detail. In 1, the best fit through a spin Hamiltonian to the experimental data of both magnetic susceptibility and magnetization curves gave Jvalues ranging from −5.5 to −11.1 cm–1. In 2, these values vary from −18.0 to −31.5 cm–1. The cluster 2also showed a magnetocaloric effect (MCE) with a −ΔSmvalue of 10.6 J kg–1K–1(16.3 J mol–1K–1) at 2.0 K. This effect is superior to that of other metallacrown compounds (with one Gd inside of an antiferromagnetic matrix of iron centers). The obtained compounds bring a new example of heptametallic clusters into a family of heteronuclear iron(III)-lanthanide derivatives with notable structural characteristics and magnetic behavior.

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