Russian Journal of Inorganic Chemistry最新文献

This paper provides a proof for the operation of analogues of the three Gibbs–Konovalov laws (Gibbs–Roozeboom rules) in solid–vapor phase diagrams of ternary systems under the conditions of solid solutions desolvation in the absence of liquid phases. The diagrams under consideration are shown to feature topological isomorphism to phase diagrams of polymorphic transformations of solid solutions in binary systems, for which analogues of the Gibbs–Konovalov laws are also formulated. The proof is based on the application of generalized van der Waals differential equations to the phase equilibrium shift, written in the metrics of the incomplete and complete Gibbs potentials of solid phases of variable composition. The applicability of the laws (rules) analogues is shown for a number of model systems. A method is proposed for the separation and purification of salt components of solid solutions based on the laws recognized for the phase diagrams of solid solutions desolvation.

Novel ethylenediamine copper(II) complex, [Cu(en)₂(H₂O)₂](2-hydroxy-2-phenylacetate)₂ have been synthesized by the addition of en (ethylenediamine) to copper(II) 2-hydroxy-2-phenylacetate in methanol : water (4:1, v/v) solution. The newly synthesised complex was characterised by elemental analyses, spectroscopic techniques (UV–Vis, FT-IR,), magnetic moment, molar conductivity measurement, thermogravimetric analysis, field electron scanning microscopy (FESEM), energy dispersive X-ray spectra (EDS) which indicated the presence of ionic complex with CuN₄O₂ chromophore. Single-crystal X-ray structural analysis revealed that copper(II) complex crystallizes in orthorhombic crystal system with Pbca space group and cell dimensions: a = 12.0266(6) Å, b = 7.9119(3) Å, c = 26.4374(12) Å, α = β = γ = 90°. Further, single crystal structure determination divulged the existence of second sphere complex with distorted octahedral geometry. Copper(II) complex consists of cationic moiety [Cu(en)₂(H₂O)₂]²⁺ and two discrete anionic moieties, 2-hydroxy-2-phenylacetate ions. Besides electrostatic forces of attraction, non-covalent interactions (hydrogen bonding and C–H···π) stitch the second sphere complex into extended three-dimensional supramolecular architecture and provide robustness to the crystal lattice. DFT investigation however displayed four coordinated distorted square planar copper(II) complex with two water molecules (at a distance < 2.593 Å) approaching the metal ion in order to provide octahedral geometry to the complex essential for packing efficiency of the crystal.

Identifying trace levels of perfluorooctane sulfonate (PFOS) at parts per trillion (ppt) in water remains a formidable task. Here, we fabricated MOF-808 through rapid microwave synthesis. Characterization of the synthesized MOF-808 involved techniques including XRD, FT-IR, SEM, and nitrogen sorption analysis. We integrated the MOF-808 as the sensing layer in a quartz crystal microbalance (QCM) sensor, specifically tailored for PFOS detection in water. Our findings revealed that the QCM sensor can detect 10 ppt of PFOS when the frequency shift is approximately 90 Hz within 50 s. Moreover, the continuous response, selectivity, and anti-interference capability of the sensor were systematically explored. This study introduces a pioneering approach for detecting ppt concentrations of PFOS in water, offering significant prospects for future applications and dissemination.

The fast-growing requirements for high-energy-density Li-ion batteries (LIBs) have prompted the research and development of Li-metal batteries (LMBs) because Li metal has a high theoretical specific capacity of 3860 mA h g^–1 and a low redox potential (−3.04 v.s. standard hydrogen electrode, SHE). However, the dendrite formation of Li metal during Li plating and stripping has exerted an enormous impedance in its commercial application. Consequently, it is imperative to exploit effective strategies to eliminate the existing issues. Three-dimensional (3D) ordered Li anode architectures with large surface area and void space, which are capable of lowering the surface current density and affording confined space to accommodate Li plating, consequently suppressing Li dendrite formation and ameliorating undesirable volume changes. More importantly, its well-aligned micro-channels can provide fast pathways for Li ion transport and promote uniform Li plating. Therefore, fabricating 3D ordered architectures is expected to remarkably boost the electrochemical stability and performance of Li anode during cycling. Herein, the important researches on the design of 3D ordered Li anode architectures for LIBs, including flexible anode, are summarized in detail. Emphasis is laid on illuminating the mechanism and the correlation between the 3D-ordered Li microstructures and the electrochemical performance of the LMBs. Furthermore, challenges and forthcoming opportunities in this promising research field are explicitly indicated. It is anticipated that this review could afford a beneficial reference to initiate further innovation in research and development of practical 3D Li anode for high-energy and safe LMBs.

Ab initio calculations have been performed on the structural, electronic, elastic, and thermodynamic properties of compounds Cs₂MF₆ (M = Cr and Ni) using the density functional theory (DFT) at the Perdew–Burke–Ernzerhof (PBE) functional. The elastic constants of the two compounds have been estimated and the values estimated verify the stability criteria, suggesting that both compounds are stable. The electronic properties of the compounds indicate that compound Cs₂CrF₆ is a semi-metal, while compound Cs₂NiF₆ behaves as a semiconductor. Using the quasi-harmonic Debye model, the thermodynamic properties of compounds Cs₂CrF₆ and Cs₂NiF₆, such as the heat capacity (C_V) and the thermal expansion (α), have also been calculated and their obtained values are analyzed and discussed. The effect of pressure and temperature on the mechanical and thermodynamic parameters has also been examined in detail in this study.

Zinc–lanthanum layered double hydroxides (Zn–La LDHs) and zinc–aluminum–lanthanum layered double hydroxides (Zn–Al–La LDHs) were prepared via a hydrothermal method. The effects of cation ratio, hydrothermal time, and hydrothermal temperature on the structure of these two types of layered double hydroxides (LDHs) and their thermal stability in polyvinyl chloride (PVC) were investigated. The optimal preparation conditions were determined to be n(M²⁺) : n(M³⁺) = 3 : 1, hydrothermal temperature of 170°C, and hydrothermal time of 8 h. The LDHs obtained under optimal conditions were characterized by X-ray powder diffraction, Fourier-transform infrared spectroscopy (FTIR), and thermal analysis. The effects of different preparation conditions of the LDHs on the thermal stability of PVC were studied through Congo red tests and high-temperature aging experiments. The results indicate that both types of LDHs significantly improve the thermal stability of PVC, with Zn–La LDHs exhibiting superior thermal stability compared to Zn–Al–La LDHs. The rare earth LDH thermal stabilizers inhibit the cleavage of C–Cl and C–H bonds in PVC, suppress the generation of HCl and C=C bonds, and reduce the catalytic effect of HCl on the degradation of PVC.

The graphene oxide (GO) microparticles were synthesized through ultrasonication for insulin delivery. The prepared GO microparticles and insulin-loaded GO/insulin composite were characterized by various techniques including ATR-FTIR (attenuated total reflection flourier transformed infrared spectroscopy), scanning electron microcopy (SEM), thermogravimetric analyzer (TG), zeta potential and dynamic lights scattering (DLS) measurements. The particle size analysis showed that the GO particle was well distributed, and the size was about 4 μm with surface charge of –27.5 mV in MES solution (pH 4.7). SEM images showed that insulin successfully attached on surface of GO particles. The GO particles exhibited excellent insulin loading efficiency in lower pH solution (2.5, 4.7). The release study showed that insulin was released from GO/insulin composite in higher pH solution (7.4). This study provides valuable information for development of insulin carriers based on GO.

The reaction between [Au(Ph₃P)Cl] and [B₂₀H₁₈]^2– in DMF gave unprecedented heptanuclear cationic gold cluster [Au₇(Ph₃P)₇@C]²⁺ isolated as [Au₇(Ph₃P)₇@C][B₂₀H₁₈][Au(Ph₃P)Cl]·0.5DMF in one step. The final compound was studied by ¹¹B NMR and IR spectroscopies, ESI MS, single-crystal and powder X-ray diffractions. No special reagents were used to obtain central carbon atom in the cluster [Au₇(Ph₃P)₇@C]²⁺.

In this work, Li_1–xMg_x/2Ѷ_x/2TaO₃ ceramic materials have been prepared for 0.00 ≤ x ≤ 0.10, where Ѷ is a vacancies site. The X-ray diffraction analysis indicated the formation of a pure phase, with no evidence of secondary phases detected. These findings confirm that all samples have crystallized into a singular pure phase, exhibiting the characteristic structural arrangement associated with the R₃C space group. The surface texture analysis of the prepared material showed a uniform distribution of grains with minimal voids, indicating high sample density. Additionally, substituting magnesium (Mg) led to a decrease in grain size, highlighting the impact of magnesium substitution on grain refinement. Ac impedance measurements were made between the temperatures of 640 and 800°C and the frequency range of 1 kHz to 2 MHz. The effect of magnesium doping Low frequency relaxation is attributed to space charges, while high frequency relaxation is attributed to ferroelectric dipoles. The electrical properties, which vary with frequency, were examined using complex impedance spectroscopy. Different types of investigations, including Nyquist plots, the real and imaginary components of impedance, conductivity, module formalism, and activation energy of charge carriers, were applied to clarify the connections between microstructure and electrical properties. The dielectric constant is high at low frequencies and decreases at moderate frequencies, indicating the Maxwell–Wagner contribution to the dielectric response. Systematic adjustments have been made with the aid of the Cole–Cole model. It appears for the identified relaxations that at temperatures close to T_C, the pass through is at its maximum and the relaxation time is thermally stable. A temperature-dependent, non-Debye relaxation process is revealed by impedance spectroscopic studies. Conductivity spectra revealed the presence of a jump mechanism in the electrical transport process. Activation energies between 1.12 and 1.39 eV indicate that the conduction of lithium vacancies takes place via a jump mechanism.

Compound Rb₃(SbF₃)(Zr₂F₁₁)·0.5H₂O and its dehydration product Rb₃(SbF₃)(Zr₂F₁₁) were synthesized and their structures were studied. It was found that compound Rb₃(SbF₃)(Zr₂F₁₁)·0.5H₂O has a unique fluoride zirconate framework structure built of ring tetrameric fragments (Zr₄F₂₄) connected to each other at the vertices by bridging fluorine atoms. Inside the tetrameric fragments, ZrF₈ polyhedra are connected to each other along common edges. The zirconium framework [Zr₂F₁₁]^3– is bound by Zr–F–Sb fluoride bridges from the second coordination sphere of antimony atoms. The structure of the dehydrated compound Rb₃(SbF₃)(Zr₂F₁₁) is a three-dimensional framework consisting of infinite chains of composition [Zr₂F₁₁]^3–. The chains are formed by ZrF₇ polyhedra connected along edges and vertices and united with each other into a three-dimensional framework by fluoride bridges Zr–F–Sb from the second coordination sphere of antimony atoms. In Rb₃(SbF₃)(Zr₂F₁₁), in the temperature range 247–256 K, a reversible phase transition occurs from the partially disordered high-temperature phase α to the ordered low-temperature phase β. With the participation of fluorine atoms of the second coordination sphere and a lone pair of electrons around antimony atoms, coordination polyhedra are formed in the structures in the form of distorted (SbEF₅) and single-capped (SbEF₆) octahedra.