Vol 86, No 9 (2016)

Magnetic susceptibility of solid solutions based on lanthanum gallate doped with iron, and also with iron, strontium, and magnesium in the ratio 5 : 1 : 1 was studied. In both systems at the infinite dilution clusters of iron atoms remain, the fraction of these clusters in lanthanum gallate doped only with iron comprising 0.4 of the total fraction of clusters in the gallate doped with strontium and magnesium.

Geometry parameters of molecular structures of pentaatomic heteronuclear Al₂M₃ clusters (M = Fe, Co, or Ni) have been simulated using hybrid density functional method (DFT) in the OPBE/TZVP approximation as implemented in GAUSSIAN 09 software. Several structure modifications have been revealed, significantly differing in the stability and geometry parameters: eight for the Al₂Fe₃ cluster, nine for the Al₂Co₃ cluster, and seven for the Al₂Ni₃ cluster. Bond lengths, bond angles, and torsion (dihedral) angles for each of these modifications are reported.

The electronic structure and features of interatomic interactions in a series of methoxysilanes H_nSi(OCH₃)_4–n (n = 3–0) were studied via density functional theory-based computer simulation and comparison of the simulated results with the photoelectron spectroscopic data. Calculations for the Si(OH)₄, SiH₄, H₂O, and CH₄ molecules were also performed in order to establish the laws governing the electronic structure formation of methoxysilanes. The distributions of the densities of electron states in the valence band and the correlation energy diagrams, supplemented by visualization of the molecular orbitals of the compounds, were constructed.

Phase composition and surface layer state of the Pd–P hydrogenation catalyst formed at various P/Pd ratios from Pd(acac)₂ and white phosphorus in a hydrogen atmosphere were determined. Palladium on the catalyst surface is mainly in two chemical states: as Pd(0) clusters and as palladium phosphides. As the P/Pd ratio increases, the fraction and size of palladium clusters decrease, and also the phase composition of formed palladium phosphides changes: Pd₃P_0.8 → Pd₅P₂ → PdP₂. The causes of the modifying action of phosphorus on the properties of palladium catalysts for hydrogenation of unsaturated compounds were considered.

Crystallization of 2,2′-bipyridine from aqueous solution containing sulfur(IV) oxide afforded clathrates with the composition (bipy)_k · (SO₂)_m · (H₂O)_n. X-Ray amorphous guest SO₂ molecules occupy voids in the crystal lattice of 2,2′-bipyridine without distortion of its structure. The isolated compounds were characterized by elemental analyses, X-ray diffraction data, and IR, NMR, and mass spectra.

Cyclocondensation of 1,4-diaminobutane and 1,6-diaminohexane with acetone afforded the corresponding 18- and 22-membered trans-azamacrocyclic Curtis compounds in high yield, which contain two azomethine and amine nitrogen atoms. A complex mixture of the products formed containing less than 25% of 16-membered azamacrocyclic cis- and trans-isomers when reacting 1,3-diaminopropane with acetone.

Condensation of aromatic, isoxazole, and ferrocene aldehydes as well as 1,1’-diacetylferrocene with 5-(4-methylphenyl)isoxazole-3-carbohydrazonamide afforded various N-substituted azines with molecular fragments of the corresponding aldehydes or diacetylferrocene.

5-(Nitrophenyl)-1,4,6-oxadithiocanes have been obtained by the reaction of p- and m-nitrobenzaldehydes with 2,2’-oxydiethanethiol in the presence of trimethylchlorosilane. The structure of the products has been proved by IR, NMR, and mass spectra.

Copolymers containing fragments of cholic acid and luminophore complexes of iridium(III) and copper(I) in the side chains have been synthesized by metathesis polymerization. Photophysical properties of the obtained compounds have been investigated. Iridium-containing copolymers demonstrate intense photoluminescence of green, bluish-green and red colors. Copper-containing copolymers generate radiation of green and yellow-green colors. The color of photoluminescence of the metal-containing polymers is determined by the nature of copper(I) and iridium(III) complexes bonded to polymer chain.

Solid phases of the [Eu(Phen)(i-Bu₂PS₂)₂(NO₃)]–[Tb(Phen)(i-Bu₂PS₂)₂(NO₃)] binary system are synthesized. The results of X-ray diffraction phase analysis and photoluminescence measurements allow the synthesized isostructural phases to be classed with substitutional solid solutions. The photoluminescence measurements revealed Tb(III)→Eu(III) energy transfer which induces Eu³⁺ luminescence.

Vaporization of a multicomponent Nb‒Si-based melt with ceramic materials containing yttrium, zirconium, hafnium, and gadolinium oxides is studied. The high-temperature reactions of the alloy and ceramics at 1795‒2510 K involve reduction of yttrium, zirconium, hafnium, and gadolinium oxides, accompanied by an increase in the partial pressures of GdO, YO, ZrO, and HfO compared with the partial pressures of the same oxides over individual ceramic samples. Ceramics oxidized titanium, silicon, aluminum, and niobium to oxides.

A process for the synthesis of a two-component vanadium-titanium-containing monolayer coating on the silica surface by treating the latter with a mixture of TiCl₄ and VOCl₃ vapors was considered. Quantum-chemical simulations showed that the synthesis temperature and concentrations of the reactants in the gas phase have a decisive influence on the composition and structure of the resulting coating. Based on the model predictions, two-component coatings with 0.2–0.9 ratios of the molar concentration of vanadium to that of titanium in the solid phase were synthesized. The ratio of the content of the solid-phase vanadium to titanium was shown to linearly vary with the VOCl₃ to TiCl₄ concentration ratio in the vapor mixture over wide temperature and concentration ranges, which allows controlling the composition of the two-component coatings being formed.

The review focuses current research in the rapidly developing field of the chemistry of porphyrin–fullerene complexes. Recent advances in the synthesis, properties, and potential applications of these compounds are considered. An overview of the most popular methods to prepare porphyrin complexes with C₆₀ fullerene is given. The discussion of porphyrin‒fullerene complexes includes the structures of noncovalently linked porphyrin‒fullerenes along with covalently linked complexes. Much attention is paid to potential applications of porphyrin‒fullerene conjugates.

Elementosiloxane oligomers were synthesized, and their properties and the reaction of cross-linking by metal porphyrazines, which are known to catalyze vulcanization of liquid low-molecular-weight elementosiloxane oligomers, were studied. The properties of the fireproof materials with vulcanized siloxane coatings based on the elementosiloxane oligomers modified with boron, aluminum, and titanium were examined. It was established that these materials have high physicomechanical and fireproofing properties.

The results of research on the correlation between molecular structure and spectral luminescent and photophysical properties for a new class of dyes and luminophores based on dipyrrins, bis(dipyrrins), and their coordination compounds in different media are summarized. The new perspective applications of dipyrrin dyes and luminophores as fluorescent sensors for measuring the polarity, viscosity, and temperature of the medium and highly sensitive and selective fluorescent “off-on” chemosensors for detecting Zn²⁺, Cd²⁺, and Hg²⁺ cations in weakly polar and nonpolar organic solvents and biological systems are discussed.

A methodology of the synthesis of 4-(8-quinolylazo)resorcinol (QAR) and 1-(8-quinolylazo)-2-naphthol (QAN) was developed. The synthesized compounds were used to modify an oxidized charcoal sorbent. The sorbent efficiently adsorbs copper(II) and zinc(II) cations to form surface electroneutral chelate complexes. The conditions of sorption and desorption of zinc(II) and copper(II) were studied.