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Nanocrystalline NaGd1–xNdxF4 (x = 0–1)phosphors have been synthesized by hydrothermal synthesis for the first time. All synthesized compounds have hexagonal β-NaYF4 crystalline phase. Neodymium(III) ions isomorphically replace gadolinium ions. NaGd0.96Nd0.04F4 compound has the largest photoemission intensity in NIR range upon 808-nm excitation; further doping with Nd3+ results in concentration quenching. [ABSTRACT FROM AUTHOR]

Microcrystalline phosphors NaY0.8–xYb0.2HoxF4 (x = 0–0.1) were first synthesized by the hydrothermal method. All synthesized compounds have hexagonal β-NaYF4 crystalline phase. It has been found that holmium(III) ions isomorphically replace yttrium ions. The maximum intensity of up-conversion emission in the visible region of the spectrum upon 973-nm excitation is observed for the compound NaY0.78Yb0.2Ho0.02F4. [ABSTRACT FROM AUTHOR]

The nanocrystalline phosphor NaGd0.7Eu0.3F4 with the most intensive luminescence among NaGd1–xEuxF4 (x = 0–1) compounds was obtained by hydrothermal synthesis. The unit cell parameters and nanoparticle size were determined. The cytotoxicity, luminescent, and magnetic properties were characterized. [ABSTRACT FROM AUTHOR]

New microcrystalline phosphors NaY1–xTbxF4 (x = 0–0.6) were obtained by the hydrothermal synthesis. All compounds have the hexagonal β-NaYF4 crystalline phase. Terbium(III) ions isomorphically replace yttrium ions, which results in increasing the unit cell parameters and decreasing the particle size. The maximum luminescence intensity is observed for the NaY0.6Tb0.4F4 compound. [ABSTRACT FROM AUTHOR]

The results of the study of ternary systems containing copper, cobalt, nickel, and cadmium halides and sulfates in binary water-organic and mixed organic solvents are summarized. The influence of the donor-acceptor properties of the ternary system components, the relative dielectric permittivity, and the intermolecular association in the mixed solvent on the solubility of salts and the crystalline structure of solvates is analyzed. [ABSTRACT FROM AUTHOR]

Four complexes [Ni(DMA)2(H2O)4]Cl2·2H2O, [Ni(DMF)2(H2O)4]Cl2·2H2O, and [Ni(DMA)6][NiCl4], [Ni(DMF)2(H2O)2Cl2] were isolated from ternary water-organic saline systems containing nickel chloride and N, N-dimethylacetamide-water and N, N-dimethylformamide-water binary solvents. The obtained complexes were studied by X-ray structural analysis. The formation of hydrogen bonds between water molecules of the nickel ion solvate sphere, chloride ions, and non-coordinated water molecules located in the cavity of the crystal structure was detected. [ABSTRACT FROM AUTHOR]

Absorption spectra of NRBr-HO and CoBr-NRBr-HO (R = Et, Bu) aqueous solutions were measured within the range of 1000-25000 cm, and the influence of tetraalkylammonium cations on the equilibrium between cobalt octahedral and tetrahedral complexes was revealed. The specificity of hydration interactions in solutions under study in various concentration ranges and resulting from them difference in spectral characteristics were analyzed. Variously directed changes in positions of bands in the region of stretching vibrations, a composite frequency of 5200 cm, and the first water overtone occurring due to the concentration variation were found. [ABSTRACT FROM AUTHOR]

A solution-solid equilibrium in ternary water-organic systems CuCl2-L-H2O (L = dimethyl sulfoxide, N,N-dimethyl formamide, and acetonitrile) at 25°C was studied. The expansion of crystallization branches of individual solvates CuCl2· xL varies in parallel to the donor power of organic solvents. The existence of the mixed crystal-solvates CuCl2·2H2O·2(CH3)2SO, CuCl2·2H2O·2(CH3)2NCHO, CuCl2·H2O·(CH3)2NCHO, CuCl2·2H2O·CH3CN, and CuCl2·3H2O·2CH3CN in the studied systems was proved. Various donor power of oxygen-containing solvents determines the composition of the first coordination sphere of the copper ion in the specified compounds: the coordination of the both solvents in the mixed crystal-solvates with DMF and the absence of water in the nearest environment of the copper(II) ions in the CuCl2·2H2O·2(CH3)2SO compound. [ABSTRACT FROM AUTHOR]

The solubility of d-metal halides in MCl2-M′Cl2-H2O systems with competitive complex formation at 25°C was discussed. The role of complex formation and hydration was traced. As the stability constants become closer to each other, the salting-in regions in the crystallization braches of both chlorides disappear. [ABSTRACT FROM AUTHOR]

The effect of the oxidation state of the metal on the solubility was analyzed using the example of CuClx-MCl-H2O ( x = 1, 2; M = Li-Cs, NH4) ternary systems. The prevalence of acido complex formation is responsible for an essential similarity of the solubility isotherms: the presence of crystallization branches of complex salts and salting-in (or weak salting-out) of copper(I) and (II) chlorides, that increases in the order LiCl < NaCl < KCl < CsCl. The different stability of copper(I) and (II) chloride complexes results in that the chemical individuality of alkali metal cations is differently reflected in the shape of the solubility isotherms: The stronger complex formation in copper(I) systems results in leveling of this effect and the weaker complex formation with copper(II), in its differentiation. [ABSTRACT FROM AUTHOR]

It was proved by the IR spectroscopy that the first coordination sphere of nickel cations in the NiCl·2DMSO·9HO, NiCl·5DMSO·4HO, and NiCl·4DMSO·2HO compounds contains dimethyl sulfoxide and water ligands. According to X-ray structural analysis, in crystals of the NiCl·4DMSO·2HO compound, noncovalent contacts between sulfur atoms of neighboring dimethyl sulfoxide molecules are realized in the inner sphere of the complex. [ABSTRACT FROM AUTHOR]

The nanocrystalline phosphor NaGd0.7Eu0.3F4 with the most intensive luminescence among NaGd1–xEuxF4 (x = 0–1) compounds was obtained by hydrothermal synthesis. The unit cell parameters and nanoparticle size were determined. The cytotoxicity, luminescent, and magnetic properties were characterized. [ABSTRACT FROM AUTHOR]

The conversion of metal-organic frameworks (MOFs) into advanced functional materials offers a promising route for producing unique nanomaterials. MOF-derived systems have the potential to overcome the drawbacks of MOFs, such as low electrical conductivity and poor structural stability, which have hindered their real-world applications in certain cases. In this study, laser scribing was used for pyrolysis of a Cu-based MOF ([Cu 4 {1,4-C 6 H 4 (COO) 2 } 3 (4,4'-bipy) 2 ] n ) to synthesize a Cu-CuO@C composite on the surface of a screen-printed electrode (SPE). Scanning electron microscopy, X-ray diffractometry, and Energy-dispersive X-ray spectroscopy were used for the investigation of the morphology and composition of the fabricated electrodes. The electrochemical properties of Cu-CuO@C/SPE were studied by cyclic voltammetry and differential pulse voltammetry. The proposed flexible electrochemical Cu-CuO@C/SPE sensor for the simultaneous detection of hydroquinone and catechol exhibited good sensitivity, broad linear range (1-500 μM), and low limits of detection (0.39 μM for HQ and 0.056 μM for CT).

Thermodynamic data on the properties of the water-based electrolyte systems are very valuable for fundamental physical chemistry and for industrial applications. The missing data both on the dilution and dissolution enthalpies for the ternary CsCl-MgCl 2 -H 2 O mixed electrolyte system were investigated by means of the calorimetry method. The dilution calorimetry was performed at 298 K for the set of solutions from diluted to concentrated at constant ratio Cs + /Mg 2+ =1.8. The relative partial molar enthalpies, ideal, total, and excess ones were calculated. By means of the dissolution calorimetry, the standard enthalpies of formation, the enthalpies, and entropies for the double salt formation from simple salts were evaluated. The results obtained indicate that entropy as the major factor affecting the formation of the joint compound, both in the liquid and solid phases. These data can be implemented in thermodynamic databases and allow for accurate thermodynamic calculations for the salts extraction from natural water sources and for its possible application as thermochemical energy storage.