Том 86, № 4 (2016)

Solubility of salts in the systems MCl₂–H₂O–Solv (M = Co, Ni) and CoBr₂–H₂O–Solv (Solv = dimethyl sulfoxide, dimethyl formamide, and dimethyl acetamide) at 25°C was measured experimentally. Dominating species of cobalt and nickel halides existing in various concentration regions were identified by analysis of electron absorption spectra. It was shown that the major factor defining solubility is the interaction of halocomplexes of metal ions with solvent molecules.

Nanocrystalline SrZrO₃ has been synthesized by a solid-state procedure using mechanical preactivation of a strontium carbonate–zirconia mixture in an AGO-2 centrifugal planetary mill. The effect of mechanical activation of the reactant mixture on the processes occurring during its subsequent heating has been studied by thermal analysis. The resulting strontium zirconate has been characterized by X-ray diffraction and by scanning and transmission electron microscopy.

Hydrogenation of carbonitriles catalyzed by nickel nanoparticles in the presence of primary amines led to the predominant formation of unsymmetrical secondary amines. In the presence of secondary amines hydrogenation of nitrites provided enamines as main products. Hydrogenation of nitriles in the presence of formamide or acetamide afforded formyl or acetyl derivatives of primary amines.

The reaction of aromatic Claisen rearrangement of N-(1-methylbut-2-en-1-yl)anilines in the presence of p-toluenesulfonic acid was investigated. N-Tosyl-2-(1-iodoethyl)-3-methylindoline derivatives were obtained; one of them exhibited a cytotoxic activity.

A method of synthesis of maleopimaric acid N-aryl(aralkyl)imidoamides by reaction of the corresponding aromatic amides of maleopimaric acid and amines in p-xylene at reflux was developed. Thermal stability of the synthesized compounds was evaluated by derivatography.

New derivatives of 2-mercaptobenzotellurazole at the three reaction centers, the thiol group, nitrogen atom and tellurium atom, have been synthesized.

4-Iodo-, 4,4′-, and 5,5′-dibromo-substituted BF2-dipyrrinates (BODIPY) have been prepared, and their spectral luminescent properties and photostability have been studied. It has been shown that the introduction of iodine and bromine atoms in the molecule structure results in build-up of the BODIPY phosphorescence and decrease in their fluorescence quantum yield. Basing on the obtained data, the prepared dipyrrinates can be recommended for development of fluorescent sensors for medical and technical applications.

Cross-condensation of 4,5-diphenoxyphthalonitrile (component A) with tetrafluorophthalonitrile (component B) in the presence of nickel(II) acetate has yielded the low-symmetry nickel phthalocyaninates of the A₃B, ABAB, and AABB types. Their spectral properties have been studied. It has been demonstrated that even at the concentration as low as (6.0–8.0) × 10^–7 mol/L the examined complexes exist in the associated form in the dichloromethane solution.

Phase-transfer catalysis and template assembly on sodium and cesium cations were used to prepare 2-(diphenylphosphoryl)phenyl ethers of ethylene glycols Lⁿ with varied number of polyether units (n = 3–8). Previously unknown dinitro and disulfo derivatives of 2-(diphenylphosphoryl)phenyl ethers of di- and triethylene glycols were synthesized. Complexes [NaL⁴]NCS·C₆H₆, [NaL⁴]ClO₄, [KL⁵]NCS, and [KL⁵]ReO₄ were synthesized, and their crystal structure was studied. Structure–stability constant correlations were found for alkali metal complexes with phosphoryl podands Lⁿ and isodentate crown ethers.

Modification of hydroxyethyl starch with glycidyl methacrylate in dimethylsulfoxide medium has resulted in the formation of the derivatives containing double C=C bonds capable of producing biocompatible hydrogels via the free-radical cross-linking. Structure of the glycidyl methacrylate derivatives has been elucidated by means of IR, UV, and NMR spectroscopy. Branching of the hydroxyethyl starch chains in the course of the interaction with glycidyl methacrylate has been observed and interpreted; the branching density has been determined. The influence of the substitution degree of the glycidyl methacrylate derivatives of hydroxyethyl starch on its melting point has been demonstrated.

Nafion-based composite solid polyelectrolytes containing fullerene C₆₀ and its water-soluble derivatives fullerenol-C₆₀ and tris-malonate-C60 were studied by the impedance spectroscopy method. It was found that introduction of these dopants in Nafion leads to a substantial increase in proton conductivity of the composites in the region of low relative humidity. The reasons for the influence of dopants on proton conductivity of composites were discussed.

The transition metal complex of Mn(II), Co(II), Ni(II), Cu(II), Ti(III), Cr(III), Fe(III), Zr(IV), and UO₂(VI) ion with a Schiff’s base ligand derived from 2-hydroxy-[2-oxo-1,2-dihydro-3H-indol-3-ylidene]-benzohydrazide have been prepared. The complexes have been characterized by elemental analysis data, IR and electronic absorption spectra, magnetic moments, and thermogravimetric analysis data. The complexes of the 1: 1 metal-to-ligand stoichiometry have been formed. The physico-chemical data have suggested the octahedral geometry for all the complexes except for Cu(II); the Cu(II) complex has been square planar. Thermal analysis data of the ligand and its complexes have been analyzed, and the kinetic parameters have been determined using the Horowitz–Metzger method. According to the solid-state electrical conductivity measurements, the ligand and its complexes are semiconducting in nature. The antimicrobial activity of the ligand and the complexes towards E. coli, S. typhi, P. aeruginosa, and S. aureus has been tested by the disc diffusion method.

Graphene oxide (GO) has been prepared by the modified Hummers method using graphite as starting material. The product was studied by the X-ray diffraction (XRD), Raman spectroscopic, transmission electron microscopic (TEM), and scanning electron microscopic (SEM) analyses. Adsorption capacity of GO for heavy metal ions was studied for the example of the Ni²⁺ ions and the adsorption kinetics and adsorption isotherm were determined. It was shown that the adsorption equilibrium curves are adequately described by the Langmuir equation.

Formation of supramolecular polysiloxane polymers was studied by using oligoamide strands 1a, 2a, and 3a bearing multiple hydrogen bonds as association units. According to SEM and TEM studies one polymeric strand associated into supramolecular spherical assemblies via duplex formation. The results demonstrated the effect of such complementary oligoamides upon constructing main-chain supramolecular polymers.

Xanthene derivatives were synthesized by a multicomponent one-pot reaction of aromatic aldehydes, β-naphthol, and 5,5-dimethylcyclohexane-1,3-dione or 1,3-cyclohexanedione upon efficient and eco-friendly catalysis of Fe(III) tetranitrophthalocyanine immobilized on activated carbon in ethanol. The method tolerated a variety of functional groups and the process was carried out under mild conditions to give high yield of products (85–91%) in 30 min. The catalyst can be recycled without any loss in catalytic activity.

A pyridinecarboxaldimine grafted to silica-coated magnetic nanoparticles was prepared. The structure and magnetic properties of the functionalized magnetic silica nanoparticles were identified by TEM, FT-IR, XRD, elemental analysis, and vibrating sample magnetometer (VSM). The supported pyridinecarboxaldimine as chelating ligand in combination with CuBr₂ and 2,2,6,6-tetramethyl-1-piperadoxyl (TEMPO) exhibited efficient catalytic performance in the aerobic oxidation of primary alcohols to aldehydes. The functionalized magnetic silica nanoparticles could be easily recovered using an external magnetic field and reused for at least 6 times with low reduction in its performance in the aerobic oxidation of benzyl alcohol.

Green microwave supported synthesis, spectral, antimicrobial, DNA cleavage, and antioxidant studies of Ge(IV) complexes with bio-potent ligands, 1-acetylferrocenehydrazinecarboxamide (L¹H) and 1-acetylferrocenehydrazinecarbothioamide (L²H) have been carried out. The ligands and their respective complexes have been characterized on the basis of elemental analysis, IR, ¹H and ¹³C NMR spectra, and X-ray powder diffraction studies. The ligands are coordinated to the Ge(IV) via azomethine nitrogen and thiolic sulfur atom/ enolic oxygen atom. Both ligands and their complexes demonstrated appreciable fungicidal and bactericidal properties. The metal complexes demonstrated stronger antimicrobial than the respective free ligands. DNA cleavage activity of the complexes study revealed higher activity of the complexes than the ligands. Antioxidant activity of the complexes was tested for their hydrogen peroxide scavenging.

Sulfacetamide complexes of Ag(I), Cu(II), and Cd(II) were synthesized and characterized by the elemental analyses and IR and ¹H NMR spectra. Structural assessment revealed two modes of coordination in the sulfacetamide complexes, showing that sulfacetamide reacts as a bidentate ligand and coordinates to Ag(I) and Cd(II) through the amido and sulfonyl oxygens and to Cu(II) through the NH₂ nitrogen. Molar conductance measurements in DMSO showed that both the complexes are nonelectrolytes in nature, which allowed they to be assigned the formulas [Ag(SAM-Na)(NO₃)H₂O)]·3H₂O, [Cu(SAM-Na)₂(Cl)₂], and [Cd(SAM-Na)(Cl)₂]·10H₂O. The kinetic and thermodynamic parameters of the thermal decomposition reactions of the complexes were estimated from the TG/DTG curves by the Coats–Redfern and Horowitz–Metzeger methods. The surface morphology of sulfacetamide complexes was scanned using X-ray powder diffraction (XRD) and scanning electron microscope (SEM) analyses.