Substitution Strategy Research Articles

Pb2Ga3F6(SeO3)2X3·2H2O (X = Cl, Br): two new HTO-type members exhibiting large NLO effects mediated by ionic mixing and substitution strategies

Pb2Ga3F6(SeO3)2X3·2H2O achieve a better balance between the large SHG effect and wide band gap in the current HTO family.

Approach for quality deep-ultraviolet nonlinear optical crystals via a substitution strategy of channel species in zeolite.

Exploring the connections between the ion substitution of a material, its crystal structure, and its performance in applications is a regular task in synthetic chemistry. However, there still remain major challenges in the substitution of polyanionic groups for single ions. Herein, a strategy of channel species substitution of single anions by polyanionic groups in a zeotype rigid framework to design a new deep-ultraviolet nonlinear zincophosphate, {[Li3Na3(SiF6)]Cs2}[(ZnPO4)6], and tune physicochemical properties was proposed.

Copper-catalyzed remote nucleophilic substitution of 5-ethynylthiophene esters

Here we demonstrate a strategy for the copper-catalyzed remote nucleophilic substitution of 5-ethynylthiophene esters at the η-position.

Inhibition of N-type calcium channels by phenoxyaniline and sulfonamide analogues.

Building on previous investigations, structural modifications to the neuronal calcium ion channel blocker MONIRO-1 and related compounds were conducted that included replacement of the amide linker with an aniline and isosteric sulfonamide moiety, and the previously used strategy of substitution of the guanidinium group with less hydrophilic amine functionalities. A comprehensive SAR study revealed a number of phenoxyaniline and sulfonamide compounds that were more potent or had similar potency for the CaV2.2 and CaV3.2 channel compared to MONIRO-1 when evaluated in a FLIPR-based intracellular calcium response assay. Cytotoxicity investigations indicated that the sulfonamide analogues were well tolerated by Cos-7 cells at dosages required to inhibit both calcium ion channels. The sulfonamide derivatives were the most promising CaV2.2 inhibitors developed by us to date due, possessing high stability in plasma, low toxicity (estimated therapeutic index > 10), favourable CNS MPO scores (4.0-4.4) and high potency and selectivity, thereby, making this class of compounds suitable candidates for future in vivo studies.

A high-rate and air-stable cathode material for sodium-ion batteries: yttrium-substituted O3-type Ni/Fe/Mn-based layered oxides

The electrochemical properties of O3-NaNi1/3Fe1/3−xMn1/3YxO2 cathode materials for sodium ion batteries are significantly improved by using yttrium substitution strategy to realize the micro-modulation of the crystal structure.

Development of commercial trout breeding in southern Russia in the context of the import substitution strategy

Aquaculture is the main promising direction for the development of the fisheries industry. Analysis of the general condition of fish breeding enterprises and the potential for expanding production shows that the growth trend of traditional for the southern regions pond fish breeding is weak. A significant problem for the development of aquaculture is the high price of fish products and, accordingly, low demand. A substantial reduction in the cost of fish production is currently unlikely to be achieved, so switching to more valuable fish varieties can stimulate consumption. To ensure the development of the fish products market and increase demand, entrepreneurs in southern Russia are improving technologies for growing such valuable fish varieties as salmonoids, in particular, rainbow trout. Studying the activities of trout farms requires taking into account which area of activity is prioritized. A farm can produce marketable fish or fish planting material, as well as execute both types of production. The work observes the organizational features of trout farms and promising directions of their development. Solving such key issues as the provision of qualified personnel, high-quality feed of domestic, preferably regional production, and provision of logistically affordable and high-quality planting material is the basis for achieving the goals of import substitution for high-quality fish products in Russia.

Optimized Allogenic Decellularized Meniscal Scaffold Modified by Collagen Affinity Stromal Cell–Derived Factor SDF1α for Meniscal Regeneration: A 6- and 12-Week Animal Study in a Rabbit Model

Background: Total meniscectomy for treating massive meniscal tears may lead to joint instability, cartilage degeneration, and even progressive osteoarthritis. The meniscal substitution strategies for advancing reconstruction of the meniscus deserve further investigation. Hypothesis: A decellularized meniscal scaffold (DMS) modified with collagen affinity stromal cell–derived factor (C-SDF1α) may facilitate meniscal regeneration and protect cartilage from abrasion. Study Design: Controlled laboratory study. Methods: The authors first modified DMS with C-SDF1α to fabricate a new meniscal graft (DMS-CBD [collagen-binding domain]). Second, they performed in vitro studies to evaluate the release dynamics, biocompatibility, and differentiation inducibility (osteogenic, chondrogenic, and tenogenic differentiation) on human bone marrow mesenchymal stem cells. Using in vivo studies, they subjected rabbits that received medial meniscectomy to a transplantation procedure to implement their meniscal graft. At postoperative weeks 6 and 12, the meniscal regeneration outcomes and chondroprotective efficacy of the new meniscal graft were evaluated by macroscopic observation, histology, micromechanics, and immunohistochemistry tests. Results: In in vitro studies, the optimized DMS-CBD graft showed notable biocompatibility, releasing efficiency, and chondrogenic inducibility. In in vivo studies, the implanted DMS-CBD graft after total meniscectomy promoted the migration of cells and extracellular matrix deposition in transplantation and further facilitated meniscal regeneration and protected articular cartilage from degeneration. Conclusion: The new meniscal graft (DMS-CBD) accelerated extracellular matrix deposition and meniscal regeneration and protected articular cartilage from degeneration. Clinical Relevance: The results demonstrate that the DMS-CBD graft can serve as a potential meniscal substitution after meniscectomy.

Partial substitution with a significant effect: coexistence of a wide band gap and large birefringence in the oxychalcogenide AEGe2O4Se (AE = Sr and Ba)

Two novel 2D oxychalcogenides, AEGe2O4Se (AE = Sr and Ba), were designed using a partial substitution strategy which exhibits the coexistence of a wide band gap (Eg > 3.1 eV) and a large birefringence (Δn > 0.2).

Thermal stability enhancement of an Mn4+-activated germanate phosphor by a cationic non-equivalent substitution strategy

The construction of a red phosphor with a negative thermal quenching effect by substituting Mg2+ with Sc3+ and its application in plant lighting.

Achieving strong second harmonic generation effects induced via dimensional increase of PbX6 octahedra and halogen substitutes in (C10H11N3)PbX4 (X = Cl or Br)

The second harmonic generation effect and birefringence of (C10H11N3)BX4 perovskites are considerably enhanced via structural evolution and halogen substitution strategies.

Modulation of luminescence properties of circularly polarized thermally activated delayed fluorescence molecules with axial chirality by donor engineering.

Multifunctional thermally activated delayed fluorescence (TADF) materials are currently a trending research subject for luminescence layer materials of organic light-emitting diodes (OLEDs). Among these, circularly polarized thermally activated delayed fluorescence (CP-TADF) materials have the advantage of being able to directly achieve highly efficient circularly polarized luminescence (CPL). The simultaneous integration of outstanding luminescence efficiency and excellent luminescence asymmetry factor (glum) is a major constraint for the development of CP-TADF materials. Therefore, on the basis of first-principles calculations in conjunction with the thermal vibration correlation function (TVCF) method, we study CP-TADF molecules with different donors to explore the feasibility of using the donor substitution strategy for optimizing the CPL and TADF properties. The results indicate that molecules with the phenothiazine (PTZ) unit as the donor possess small energy difference, a great spin-orbit coupling constant and a rapid reverse intersystem crossing rate, which endow them with remarkable TADF features. Meanwhile, compared with the reported molecules, the three designed molecules exhibit better CPL properties with higher glum values. Effective molecular design strategies by donor engineering to modulate the CPL and TADF properties are theoretically proposed. Our findings reveal the relationship between molecular structures and luminescence properties of CP-TADF molecules and further provide theoretical design strategies for optimizing the CPL and TADF properties.

Hierarchically stabilized Pt single-atom catalysts induced by an atomic substitution strategy for an efficient hydrogen evolution reaction

Tuning and stabilizing the chemical microenvironment of Pt-based single-atom catalysts is a major challenge in promoting an electrocatalytic hydrogen evolution reaction (HER).

Electronic effects of conjugated aryl groups on the properties and reactivities of di(arylethynyl)tetracenes.

The photochemical oxidations of acenes can cause challenges with their optoelectronic applications, such as singlet fission and organic transistors. At the same time, these reactions form the basis for many luminescent sensing schemes for 1O2. While diethynyl substitution is arguably the most widely adopted of the various substitution strategies to control oxidation and also improve solubility and processability of long acenes, the extent to which differences between the alkyne groups can influence key properties of long acenes remains largely unknown. This report therefore describes the effects of various arenes and heteroarenes on the electronic structures, optical properites, and reactivity with singlet oxygen for eight 5,12-di(arylethynyl)tetracenes. The fluorescence spectra of these tetracenes span approximately 100 nm, while their observed rate constants for reaction with singlet oxygen correlates strongly with the HOMO level, spanning one order of magnitude. They are also amenable to fluorescent materials that respond ratiometrically to singlet oxygen. Therefore, electronic effects of groups directly conjugated to ethynylacenes offer a useful chemical space for rational acene design.

Synthesis of highly soluble zirconium organic cages by iodine substitution toward a CO2/N2 separation membrane.

Metal organic cages (MOCs) show promise as fillers in mixed-matrix membranes (MMMs) for gas separation; highly soluble MOCs are desirable for fabrication of high-compatibility membranes. Herein, we report an iodine substitution strategy to substantially increase the MOC solubility. The synthesized MOC of ZrT-NH2-I possesses over 10-fold higher solubility than the parent ZrT-NH2 in organic solvents whilst retaining the original molecular structure and permanent porosity. Such enhanced solubility allows for the effective integration of ZrT-NH2-I with an amidoxime polymer of intrinsic microporosity (PIM-PAO), resulting in a compatible MMM with a uniform distribution of MOC. The ZrT-NH2-I@PIM-PAO MMM demonstrates a CO2 permeability of 1377 barrer and a CO2/N2 gas selectivity of 45 which is 45 times that of the membrane made from ZrT-NH2. The permeability-selectivity performance not only surpasses the 2008 upper bound, but also exceeds those of currently available MMMs.

Chiral three-dimensional organic-inorganic lead iodide hybrid semiconductors.

Chiral hybrid metal halides (CHMHs) have received a considerable amount of attention in chiroptoelectronics, spintronics, and ferroelectrics due to their superior optoelectrical properties and structural flexibility. Owing to limitations in synthesis, the theoretical prediction of room-temperature stable chiral three-dimensional (3D) CHFClNH3PbI3 has not been successfully prepared, and the optoelectronic properties of such structures cannot be studied. Herein, we have successfully constructed two pairs of chiral 3D lead iodide hybrids (R/S/Rac-3AEP)Pb2I6 (3R/S/Rac, 3AEP = 3-(1-aminoethyl)pyridin-1-ium) and (R/S/Rac-2AEP)Pb2I6 (2R/S/Rac, 2AEP = 2-(1-aminoethyl)pyridin-1-ium) through chiral introduction and ortho substitution strategies, and obtained bulk single crystals of 3R/S/Rac. The 3R/S exhibits optical activity and bulk photovoltaic effect induced by chirality. The 3R crystal device exhibits stable circularly polarized light performance at 565 nm with a maximum anisotropy factor of 0.07, responsivity of 0.25 A W-1, and detectivity of 3.4 × 1012 jones. This study provides new insights into the synthesis of chiral 3D lead halide hybrids and the development of chiral electronic devices.

Проблеми імпортозаміщення та їх вирішення на машинобудівних підприємствах

The article presents the results of a study of the problem of import substitution at two levels of management, namely: macro- and micro-level. The aim of the article is to substantiate the scientific, methodical and practical aspects of import substitution in the current conditions of enterprise activity. On the basis of the analysis of the works of well-known experts on the problems of export-import activity, it is proposed to consider import substitution as a process of ensuring the efficiency of activity by: production of own competitive products with high added value; replacement of imported raw materials, materials and components with domestic ones that have a lower cost; diversification of production of quality products of lower value, which replaces imported products in the domestic market. Such a definition specifies the ways of import substitution in the conditions of a real enterprise. The problems and prospects of implementation of the import substitution strategy in the machine-building industry are considered. An analysis of the implementation of the import substitution strategy at the enterprise of JSC «Ukrainian Energy Machines» has been carried out. Some aspects of methodological support for determining import substitution at enterprise have been proposed. A multifactorial regression model of dependence of profitability of enterprise activity on the volume of exported products and volumes of imported raw materials, materials and components has been developed. On the basis of the SWOT analysis, effective ways to implement the import substitution strategy at the enterprise to improve the efficiency of its activities have been identified.

Технологический суверенитет и образовательная политика

The article is devoted to one of the most urgent problems – the staffing of technological sovereignty of Russia. The author analyzes the factors that actualize this problem, including the imprecisely formulated import substitution strategy. In the author's opinion, the most acute problems of educational policy in this regard are the training of highly qualified workers, engineers and teachers. The article formulates specific proposals, the general meaning of which is financial and social prioritization, which makes it possible to reduce or overcome the personnel shortages in the relevant areas of the national economy.

Effect of two-fold single-atom substitutions (S, Se; C, N) in band gap engineered donor-acceptor conjugated microporous polymers on the efficient aerobic photooxidation of aryl sulfides.

Substitution of a single atom in a photoactive system is capable of vastly altering its optoelectronic properties leading to the generation of an efficient photocatalyst. In this study, we explore the impact of two-fold single-atom substitutions on the optoelectronic properties and photocatalytic performance of donor-acceptor type conjugated microporous polymers (D-A CMPs). For this, three isostructural triphenylamine (TPA)-based D-A CMPs were synthesized namely PTPA-BT, PTPA-BS, and PTPA-PS containing 2,1,3-benzothiadiazole, 2,1,3-benzoselenadiazole and [1,2,5]selenadiazolo[3,4-c]pyridine as the acceptor moieties, respectively. Firstly, PTPA-BT and PTPA-BS were synthesized using the S to Se single-atom substitution strategy, followed by the synthesis of PTPA-PS employing a second C to N single-atom substitution. The effect of single-atom substitution demonstrated drastic changes in their band gap, conductivity, and charge carrier dynamics, which in turn impacted their photocatalytic activity, although the change in their porosity was not much pronounced. In terms of photocatalytic detoxification of sulfur mustards, the activities of D-A CMPs follow the trend: PTPA-BS > PTPA-PS > PTPA-BT. In comparison with PTPA-BT (containing C, S) and PTPA-PS (containing N, Se), PTPA-BS (containing C, Se) exhibits a higher photocatalytic activity towards the photooxidation of thioanisole with >99% conversion and ∼93% isolated yield under visible-light illumination, which is attributed to its lower interfacial charge transfer resistance, stronger photocurrent response, optimal band gap and higher activity to generate superoxide anion radicals. Therefore, the two-fold single-atom substitution strategy is crucial for optimizing D-A CMPs for the photocatalytic oxidation of aryl sulfides. This approach allows fine-tuning of the optoelectronic properties to enhance photocatalytic efficiency and performance.

Using a dual-site substitution strategy to inhibit staircase-like electrochemical profiles for high-performance Na-ion battery cathodes

The dual-site substitution strategy is utilized in improving the electrochemical behaviors of layered oxide cathodes and provides a synergistic modification method to achieve high-performance layered cathodes for Na-ion batteries.

Anion Substitution Strategy toward an Advanced NASICON-Na4Fe3(PO4)2P2O7 Cathode for Sodium-Ion Batteries.

Superior sodium-ion batteries (SIBs) greatly need cathode materials with higher capacity and better durability. Herein, the anion group substitution strategy is proposed to design a cathode material with extraordinary Na+ storage performance, NASICON-Na4Fe3(PO4)1.9(SiO4)0.1P2O7 (NFPP-Si0.1). The experimental and theoretical research revealed that modification in the local structure by anion substitution significantly boosts the ionic/electronic transfer kinetics via optimizing the electronic conductivity and reducing the Na+ diffusion energy barrier. Furthermore, the SiO44- substitution generates a slight expansion of the crystal lattice to broaden the Na+ diffusion channel. Specifically, the custom-designed NFPP-Si0.1 could deliver a high rate capability of 77.6 mAh g-1 at constant 50 C charge-discharge and excellent recyclability of 79.4% retention rate after 7000 cycles at 10 C. Besides, it also possesses outstanding low temperature reversible capacity of 95.5 mAh g-1 at 0.1 C and long-term cyclability of 93.6% capacity retention after 1000 cycles at 5 C in -10 °C. This strategy of heterogeneous and isostructural anion group substitution provides a method for unlocking high-rate and long-life-span mixed polyanionic cathodes.