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A new heterometallic complex of CoII and NdIII with phenathroline [Co(Phen)3][Nd(NO3)5(H2O)][Nd(NO3)4(H2O)2]⋅H2O was synthesized for the first time by the self-assembly method. The crystal structure of the complex was determined by X-ray crystallography. The compound is an anion-cation complex and crystallizes in the monoclinic space group P21/n with unit cell parameters à=12.4251(4) Å, b=11.7206(3) Å, c=36.5374(12) Å, α=γ=900, β=90.581(3)0 . In the crystalline phase, the complex is in the form of a crystal hydrate with a composition of 1:1. The anionic part of the complex consists of two nitrate hydrated NdIII complexes: [Nd(NO3)5(H2O)][Nd(NO3)4(H2O)2]–, in which the coordination number of neodymium is 11 and 10, respectively. The [Co(Phen)3]3+ ion is a cationic part of the complex in which the CoII atom has a distorted CoN6 octahedral environment, bidentately coordinating three phenanthroline molecules. Due to intermolecular hydrogen bonds (N–H⋅⋅⋅O, O–H⋅⋅⋅O), a three-dimensional supramolecular architecture is formed in the crystal, in which the polymer layers are packed parallel along the crystallographic axis a. [ABSTRACT FROM AUTHOR]

Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the effect of pH and the Co:Rut ratio on redox potentials and electrical conductivity of water-alcohol solutions of Co(II) complexes with rutin (Rut). It was found that the reduction potentials for the ratio Co:Rut=1:1 and 1:2 are in the range of -0.110 V to - 0.197 V relative to the Ag/AgCl reference electrode, which is significantly higher than the potentials for known flavonoids. In an alkaline medium, the absolute value of the reduction potential increases regardless of the composition of the sample. The measured range of oxidizing potentials for all compounds is in the range of +0.02 V to +0.094 V relative to Ag/AgCl reference electrode, which corresponds to the potentials of compounds with self-oxidizing activity. It is assumed that an increase in oxidative potentials up to 0.094 V can characterize the antioxidant activity, which is associated with the manifestation of the autoxidizing properties of the complex in the presence of oxygen and is due to the participation of different binding sites in chelation with the metal. Using the data of electrochemical impedance spectroscopy, the capacity of electrical double layer of a platinum electrode in water-alcohol solutions containing Co(II) complexes with rutin was calculated. An increase in capacitance values by an order of magnitude was observed at a ratio of metal:ligand=2:1 in comparison with the complexes having a ratio of 1:1. The effect of an excess of hydroxyl ions on the charge distribution at the electrode/solution interface was experimentally established, leveling the effect of the Co:Rut ratio on the electrochemical properties. [ABSTRACT FROM AUTHOR]

The paper reports the results of the study on the synthesis of new heterometallic complexes of Co(II) and Nd(III) with succinic acid in the presence of 1,10-phenanthroline or pyridine. The following hetero- and monocomplexes were synthesized: [Co(C4H4O4)-2Py]-2H2O and [Co(C4H4O4)- Phen].2H2О; [Nd,(C4H4O4)3]5H2О and [Nd(C4H4O4)3 2Phen]2H2O; [Co2Nd2(C4H4O4)54Py]4H2O and [Co2Nd2(C4H4O4)52Phen]4H2O (Phen - phenanthroline, and Py - pyridine). The study of their composition, structure, thermal properties and determination of the ability of he-terocomplexcs to form complex oxides was carried out. The complexes were characterized by a number of physicochemical methods: elemental analysis, IR- and diffuse reflection spectroscopies, X-ray powder diffraction and differential thermal analysis. Based on the analysis of diffuse reflection spectra and IR spectra ofhcterocomplexcs, it was shown that succinic add and 1,10-phenanthroline are bidentatcly bound to metal atoms. The metals arc connected by succinic acid, forming a chain. Oxide powders were obtained during thermolysis of hc-tcrocomplcxcs up to 00°C. The-composition of the synthesized hcteromctallic compounds was controlled by X-ray powder diffraction. It was shown that a complex oxide of NdCoO3 (cubic crystal system), without impurities, was formed, when the heterocomplex of phenanthroline [Co2Nd2(C4H4O4)3-2 Phen]-411,0 was heated to 800°C. When heating the heterocomplex of pyridine [Co2Nd2(C4H4O4)5-4Py]-4H2O, in addition to the complex oxide-NdCoO3, oxides Nd2O3 (hexagonal crystal system), Nd2O3 (cubic crystal system) and Co3O4 oxide-(cubic crystal system) were forme-d. The he-terocomplex [Co2Nd2(C4H4O4)5-2Phcn]-4H2O can be used as a precursor for the synthesis of cobaltate of neodymium with lower energy costs than in solid-phase synthesis. [ABSTRACT FROM AUTHOR]

New mono- and heteroligand (with phenanthroline or dipyridyl) metal complexes of ytterbium (III) with 2-methyl-5-biphenylpentene-1-3,5-dione were synthesized in this work. Homo- and copolymers of ytterbium complex with methyl methacrylate or styrene were obtained by the method of radical polymerization. Coordination compounds were investigated by IR spectroscopy, diffuse reflectance spectroscopy, thermal and luminescence analyses. It was determined that the β-diketone molecules are bidentate-cyclically coordinated to the central atom, and the coordination sphere of the monoligand complex is supplemented by two water molecules, which in the case of heteroligand complexes (HLC) are replaced by phenanthroline or dipyridyl molecules. An increase in thermal stability of heteroligand complexes and metallopolymers was observed compared to the metallocomplex. The spectral properties of the synthesized compounds were studied and it was established that the structure of the coordination node of the elementary link of polymer macromolecules does not change during the polymerization process. It was shown that all the studied samples exhibited 4f-luminescence in the near-infrared region of the spectrum, while the lowest relative luminescence intensity was characteristic of ytterbium(III) homopolymer and copolymers, and the highest values were shown by heteroligand complexes with phenanthroline, which allows us to propose them as precursors of luminescent materials. [ABSTRACT FROM AUTHOR]

This work presents the results of studies aimed at determining the conditions for the synthesis of a new heterometallic complex of Co(II) and Nd(III) with oxalic acid in the presence of 1,10-phenanthroline, studying its composition, structure, thermal properties and its ability to form complex oxides. The hetero- and monocomplexes [Co(C2O4)·Phen]2·4H2O, [Nd2(C2O4)3·2Phen], [Co2Nd2(C2O4)5·2Phen]·4H2O (Phen -- phenanthroline) were synthesized. The complexes were investigated by the following physicochemical research methods: elemental analysis, differential thermal analysis, IRand diffuse reflection electronic spectroscopies, and X-ray powder diffraction. Based on the analysis of electronic and IR spectra, it was shown that ions of metals bind bidentately with ions of oxalates and with molecules of 1,10-phenanthroline. The structures of the ion of cobalt and ion of neodymium correspond to the distorted octahedron. The ions of metals are bound together by oxalate ligands. The powders of oxides were prepared by thermolysis of the heterocomplex up to 800 °C and 1000 °C. The composition of the obtained oxide powders was controlled by X-ray powder diffraction. When the heterocomplex is heated to 800 °C, in addition to the complex oxide NdCoO3, we obtained the following oxides: Nd2O3 (hexagonal crystal system), Nd2O3 (cubic crystal system) and Co3O4 (cubic crystal system). After heating to 10000C, a more pure complex oxide NdCoO3 was obtained. Neodymium cobaltate NdCoO3 crystallizes in the cubic crystal system, the unit cell parameter is a=3.770 Å, the cell volume is 53.568 Å3. The average crystallite size was calculated using the Scherrer formula, and it is equal to ~35 nm. The synthesized heterometallic complex [Co2Nd2(C2O4)5·2Phen]·4H2O can be used as a precursor for the preparation of cobaltate of neodymium with lower energy consumption than in solidphase synthesis. [ABSTRACT FROM AUTHOR]

The method of impedance spectroscopy was used to study the conductivity of the films of sodium salt of 2-methyl-5-phenylpenten-2-3-5-dione (Namphрd) and polymer based on it that were prepared using drip application from various solvents. It was shown that the use of different solvents when applying films from solutions allows to obtain materials with different types of conductivity due to the specific solvation of the materials. [ABSTRACT FROM AUTHOR]