Malonate ligands demonstrate versatility for intercalating metal complexes into layered rare-earth hydroxides (LREHs), enabling controlled tuning of coordination geometry and composition. As a proof of concept, a series of copper(II) malonate complexes with various substituents was synthesized and successfully intercalated into layered yttrium, europium, or terbium hydroxide at room temperature via anion-exchange reactions. The copper content in these hybrid materials increased in the order: butylmalonate < benzylmalonate < cyclopropanedicarboxylate < dimethylmalonate. To further expand the range of accessible metal malonate complexes, dimethyl- and benzylmalonate anions were intercalated into layered yttrium hydroxide for the first time and subsequently metalated in situ, yielding well-defined Cu2+ species within the interlayer space without disrupting the host lattice. Density functional theory (DFT) calculations provided insight into the structural arrangements of the copper complexes in the interlayer galleries. Comprehensive characterization of the resulting materials by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), IR, UV-vis, and electron paramagnetic resonance (EPR) spectroscopy confirmed both the successful formation of hybrid structures and elucidated the coordination environment of the intercalated copper species.

Hydrothermal treatment of nanoscale ThO 2 in a sodium–phosphate buffer yields a previously uncharacterized hydrated sodium–thorium phosphate with pH-dependent phase evolution.

The fluorination processes of layered rare-earth hydroxides (LRHs) intercalated with various anions, including organic ones, have been compared for the first time. The fluorination process was investigated for chloride-, nitrate- and 4-sulfobenzoate-intercalated Eu-doped layered yttrium hydroxides by interaction with aqueous solutions of sodium fluoride at 100-150 degree celsius for 2-48 hours. The final product of fluorination in all cases is the hexagonal yttrium hydroxide fluoride (YHF) phase of NayY0.95Eu0.05(OH)(3+y-x)F-x center dot mH(2)O (x similar to 3, y similar to 0.2) composition. The formation rate of the YHF increases with the interlayer spacing of the Eu-doped layered yttrium hydroxide.

A BSTRACT A method for low-temperature synthesis of InFeZnO4 oxide from an X-ray amorphous precursor formed as a result of the thermal decomposition of dehydration product of a mixture of polyvinyl alcohol and iron, indium, and zinc nitrate solutions has been developed. Using TG/DSC and XRD, the InFeZnO4 phase has been shown to be formed in the temperature range of 370-420 degrees C. Using the XRD method, after the heat treatment of the precursor at 800 degrees C for 4 hours, nanocrystalline InFeZnO4 with an average particle size (CSR) of approximate to 36 nm has been found to be formed. According to SEM, they do not have a clear facet and form a homogeneous cellular microstructure of the powder. The absence of organic residues and moisture in it has been confirmed by FTIR spectroscopy. From the DRS data, it has been found that the band gap energy Eg of InFeZnO4 for the cases of indirect and direct transitions is 1.54 eV and 2.25 eV, respectively. Ceramics produced from nanocrystalline InFeZnO4 by high-temperature sintering have a density equal to 5160 kg/m3 (approximate to 86 % of the theoretical one). Their microhardness, measured by the Vickers method, is 2.12 GPa. The radiation resistance of InFeZnO4 has been predicted, from which it follows that, when exposed to intermediate and high doses of ionizing radiation, its partial amorphization is the most likely.

To maintain the single-phase nature of the cubic solid solution Ba2(Y, Cu, Mo)2O6, which is prone to polymorphism, titanium oxide was used. As a result of the synthesis by gel burning, annealing at 1000°C, and subsequent cooling in an inertial thermal mode, the cubic modification F 4̅ 3m of Ba5Y2CuMoTiO14 was obtained for the first time without an admixture of perovskite Fm3m. A comparative study of samples Ba4Y2CuMoO11 and Ba5Y2CuMoTiO14 was carried out using X-ray powder diffraction, X-ray fluorescence spectrometry, IR spectroscopy, and diffuse reflectance spectroscopy.

The synthesis of multicomponent and high-entropy compounds has become a rapidly developing field in advanced inorganic chemistry, making it possible to combine the properties of multiple elements in a single phase. This paper reports on the synthesis of a series of novel high-entropy layered rare earth hydroxychlorides, namely, (Sm,Eu,Gd,Y,Er)2(OH)5Cl, (Eu,Gd,Tb,Y,Er)2(OH)5Cl, (Eu,Gd,Dy,Y,Er)2(OH)5Cl, and (Eu,Gd,Y,Er,Yb)2(OH)5Cl, using a homogeneous hydrolysis technique under hydrothermal conditions. Elemental mapping proved the even distribution of rare earth elements, while luminescence spectroscopy confirmed efficient energy transfer between europium and other rare earth cations, thus providing additional evidence of the homogeneous distribution of rare earth elements within the crystal lattice. The average rare earth cation radii correlated linearly with the unit cell parameters (0.868 < R2 < 0.982) of the high-entropy layered rare earth hydroxychlorides. The thermal stability of the high-entropy layered rare earth hydroxychlorides was similar to that of individual hydroxychlorides and their binary solid solutions.

Molecular solid solutions of yttrium and dysprosium lactates of composition [Y1–xDyx(C3H5O3)3(H2O)2], where x = 0, 0.01, 0.1, 0.5, 0.8, and 1, have been obtained for the first time. These solutions can be considered as the first examples of REE coordination compounds formed due to hydrogen bonding. The obtained compounds have been analyzed by the set of physicochemical methods including XRD, energy dispersive X-ray (EDX), IR, and Raman spectroscopy. Unit cell volume of solid solutions shows linear dependence on cationic composition. It has been found that variation in the cationic composition of solid solutions leads to the monotonic shift of position of lines in Raman spectra corresponding to vibrations of Ln–O bonds (151–158 cm–1). It has been shown that the obtained compounds can behave as single-molecule magnets with magnetization barrier up to 108 K.

This work reports on the possibility of producing oxide InGaMgO4 by two-stage heat treatment of glycine-, starch- and PVA-nitrate precursors. The products formed as a result of their heating at low temperatures (≈ 90°С) were studied by powder X-ray diffraction. It was found that the powder formed from the glycine-nitrate precursor contains nanocrystalline In2O3, and drying of the polymer-nitrate compositions leads to the production of a thermally stable X-ray amorphous product. Its annealing at temperatures above 800°C allows synthesizing powder InGaMgO4 free of impurity phases. High-temperature treatment of the powder formed from the glycine-nitrate precursor also leads to the production of InGaMgO4, but does not remove the In2O3 impurity. Using scanning electron microscopy, it was found that single-phase InGaMgO4 powders synthesized from polymer-nitrate precursors have a similar grain structure but differ in grain size distribution. Presumably, this difference is due to the structural features of starch and PVA macromolecules used for the preparation of precursors. Oxide InGaMgO4 was characterized using differential scanning calorimetry, Raman and diffuse reflectance spectroscopy. The value of its band gap energy Eg was determined using the Tauc method.

In this paper, a method was proposed for the synthesis of one-dimensional nanoparticles based on new rare earth (RE) compounds, RE hydroxyglycinates. One-dimensional nanoparticles were obtained by the interaction of RE oxides (Y2O3, Eu2O3, Ho2O3, Er2O3, Gd2O3, Sm2O3) with glycine solutions at the molar ratio NH2CH2COOH : RE2O3 = 35 : 1 at 60°C. The thickness of nanoparticles was 50–150 nm and the length was 1–5 μm. FT-IR and Raman spectroscopy, thermal analysis and CHN elemental analysis data allowed to establish that the composition of the hydroxyglycinate nanorods is described by the formula Ln(NH2CH2COO)1.2(OH)1.4(CO3)0.2·1.2H2O. Based on atomic force microscopy data, the Young’s modulus of one-dimensional europium hydroxyglycinate nanoparticles was determined ( 35 GPa) and the lower limit of the shear modulus was estimated ( ≫ 2.0 GPa).

The dehydration–rehydration process of layered hydroxides is an example of a reversible chemical reaction involving rearrangement of the crystal structure. Products of thermal decomposition of layered rare earth hydroxides are known to react under certain conditions with aqueous salt solutions and restore their original layered structure. In the present work, the effect of the temperature and duration of thermal treatment of the layered rare earth hydroxychlorides at 100–1150°C on the reaction of the obtained products with aqueous sodium chloride solution was systematically studied for the first time. The main stages of the thermal decomposition of layered rare earth hydroxychlorides were determined by the thermogravimetric analysis. X-ray powder diffraction analysis and energy-dispersive X-ray spectroscopy were used to determine the phase and the chemical composition of the products of thermal treatment and subsequent rehydration of the layered hydroxides. It was shown that the presence of the rare earth oxychloride phase in the products of thermal decomposition was a critical factor for the recovery of the layered structure.

A new phase Ba2(Y,Cu,Mo)2O6 with the cubic perovskite structure Fm-3m has been obtained in the BaO–CuO–Y2O3–MoO3 quasiquaternary system, and the possibility of coexistence of two limited solid solutions with cubic structures Fm-3m and F-43m has been established. The samples were synthesized by gel combustion followed by calcination at 1000°C and cooling in the inertial thermal regime. The studies were carried out by X-ray phase analysis, X-ray fluorescence spectrometry, infrared spectroscopy, and diffuse reflectance spectroscopy.

A series of yttrium subgroup rare earth elements (REE) lactates of [Ln(C3H5O3)(3)(H2O)(2)] (Ln = Tb-Lu) composition isostructural to yttrium lactate has been prepared for the first time. Synthesis of crystalline REE lactates has been performed from solutions of REE nitrates in the presence of L-lactic acid and hexamethylenetetramine. The composition and structure of the obtained compounds have been confirmed by X-ray powder diffraction, thermal, and chemical (CHN) analysis. The coordination type of lactate anions to REE cations has been determined by IR spectroscopy. Thermal decomposition of REE lactates at 800 degrees C leads to formation of nanocrystalline (20-40 nm) REE (Y, Tb-Lu) oxides.

Samples of Mg3 – nNinBPO7 (n = 0–3), synthesized by gel combustion followed by annealing at 980°C and cooled in the inertial-thermal mode, were studied by X‑ray powder diffraction, infrared spectroscopy, and X-ray fluorescence spectrometry. For the first time, the crystalline phase of Ni3BPO7 with the β-Zn3BPO7 structure has been experimentally obtained. When the composition of the samples changed from Mg3BPO7 to Ni3BPO7, a region of coexistence of α‑Mg3BPO7 and β-Ni3BPO7 phases was found. An analysis of the diffuse reflectance spectra of the Mg1.5Ni1.5BPO7 sample showed the presence of Ni2+ cations in an arrangement not symmetric octahedral or tetrahedral.

A series of yttrium subgroup rare earth elements (REE) lactates of [Ln(C3H5O3)3(H2O)2] (Ln = Tb–Lu) composition isostructural to yttrium lactate has been prepared for the first time. Synthesis of crystalline REE lactates has been performed from solutions of REE nitrates in the presence of L-lactic acid and hexamethylenetetramine. The composition and structure of the obtained compounds have been confirmed by X-ray powder diffraction, thermal, and chemical (CHN) analysis. The coordination type of lactate anions to REE cations has been determined by IR spectroscopy. Thermal decomposition of REE lactates at 800°C leads to formation of nanocrystalline (20–40 nm) REE (Y, Tb–Lu) oxides.

Mg 3 – n Ni n BPO 7 samples ( n = 0–3) were synthesized by gel combustion followed by annealing at 980°C, cooled under inertial-thermal conditions, and then studied by X-ray powder diffraction analysis, IR spectroscopy, and X-ray fluorescence spectrometry. A crystalline phase of Ni 3 BPO 7 with the β-Zn 3 BPO 7 structure was experimentally obtained for the first time. When varying the composition of the samples from Mg 3 BPO 7 to Ni 3 BPO 7 , in borophosphate, a region of coexistence of α‑Mg 3 BPO 7 and β-Ni 3 BPO 7 was discovered. Analysis of diffuse reflectance spectra of Mg 1.5 Ni 1.5 BPO 7 showed the presence of Ni 2+ cations in an environment different from the symmetrical octahedral or tetrahedral environment.

Samples of the composition Ce 0.9 (Mg 1 – x Ni x ) 0.1 O 2 (0 ≤ x ≤ 1, step x = 0.1) have been obtained by gel combustion followed by hydrothermal treatment. X-ray powder diffraction data have showed that after gel combustion and annealing at 1100°C, composite CeO 2 (fluorite structure)/solid solution Mg 1 – x Ni x O (halite structure) is formed, and additional hydrothermal treatment followed by annealing promotes the formation of limited solid solution Ce 0.9 (Mg 1 – x Ni x ) 0.1 O 2 . According to the results of IR spectroscopy, the CeO 2 /Mg 1 – x Ni x O composite does not adsorb CO 2 even in the presence of water vapor, which is also confirmed by diffuse reflectance spectra in the UV-visible region. On the contrary, the Ce 0.9 (Mg 1 – x Ni x ) 0.1 O 2 solid solution absorbs CO 2 , as evidenced by the results of IR spectroscopy and thermogravimetric analysis.

The Mg3 – nNinBPO7 (n = 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0) samples were prepared by solid-phase reactions at 980°C followed by inertial cooling, and then were characterized by X-ray powder diffraction, IR spectroscopy, diffusive reflectance and X-ray fluorescence spectrometry. It was for the first time that experiments yielded Ni3BPO7 crystals having the β-Zn3BPO7 non-centrosymmetrical hexagonal structure. The α-Mg3BPO7 and Ni3BPO7 coexistence range was determined. The diffuse reflectance spectra of an Mg1.5Ni1.5BPO7 sample featured a strong Ni2+ absorption band in the blue spectral range.

Samples of the composition Ce0.9(Mg1 – xNix)0.1O2 (0 ≤ x ≤ 1, step x = 0.1) have been obtained by gel combustion followed by hydrothermal treatment. X-ray powder diffraction data have showed that after gel combustion and annealing at 1100°C, composite CeO2 (fluorite structure)/solid solution Mg1 – xNixO (halite structure) is formed, and additional hydrothermal treatment followed by annealing promotes the formation of limited solid solution Ce0.9(Mg1 – xNix)0.1O2. According to the results of IR spectroscopy, the CeO2/Mg1 – xNixO composite does not adsorb CO2 even in the presence of water vapor, which is also confirmed by diffuse reflectance spectra in the UV-visible region. On the contrary, the Ce0.9(Mg1 – xNix)0.1O2 solid solution absorbs CO2, as evidenced by the results of IR spectroscopy and thermogravimetric analysis.

The Mg3 – nNinBPO7 (n = 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0) samples were prepared by solid-phase reactions at 980°C followed by inertial cooling, and then were characterized by X-ray powder diffraction, IR spectroscopy, diffusive reflectance and X-ray fluorescence spectrometry. It was for the first time that experiments yielded Ni3BPO7 crystals having the β-Zn3BPO7 non-centrosymmetrical hexagonal structure. The α-Mg3BPO7 and Ni3BPO7 coexistence range was determined. The diffuse reflectance spectra of an Mg1.5Ni1.5BPO7 sample featured a strong Ni2+ absorption band in the blue spectral range.

Biomineralization is a universal process that has implications in a variety of areas, from civil engineering to medicine. While crystallization of amorphous CaCO3 formed in vitro is known to precede the vaterite-calcite/aragonite pathway, this process could be significantly altered when induced by bacteria, particularly within the extracellular matrix (ECM) of microbial cells. We used a combination of SEM, SANS, SAXS, FTIR and XRD methods to investigate the structure of CaCO3 formed during biomineralization induced by planktonic Bacillus cereus. Formation of precipitates in the presence of CaCl2 and urea was observed both during bacterial growth and in the medium devoid of bacteria and ECM (cell-free system). The pathway for polymorphic transformations of CaCO3 from the amorphous phase to vaterite and further to calcite was confirmed for the bacterium-induced mineralization and did not depend on the concentration of Ca2+ and urea. The structure of CaCO3 sediments differed when formed in cell-free and bacterial systems and varied depending on time and the medium composition. The rate of precipitation was accelerated in the presence of DNA, which had little effect on the solid phase structure in the cell-free system, while strongly affecting the structure and polymorphic composition of the precipitates in bacterial culture.