A matrix method for calculating the magnetic properties of Co2+ complex ions

A matrix method for calculating of the magnetic properties of Co²⁺ complex ions is proposed. The method involves calculations of a full matrix of all interactions existing in the ion. The theoretical results obtained by this method more accurately describe the observed experimental values of magnetic parameters of mononuclear complexes with Co²⁺ ions.     

Application of symmetry groups of four-dimensional space in spectroscopy of crystals

A method of classification of many-electron states that involves symmetry groups of four-dimensional space is developed. Taking into account the spatial and temporal symmetry, the selection rules for electric and magnetic dipole transitions are investigated. The reduction relations for the irreducible representations of the orthogonal group O ₄ and the group R ₄ of pure rotations of the four-dimensional space on the groups and O _h ⁴ and O ⁴ of the four-dimensional cube and of the octahedron on the three-dimensional groups O _h and D _6h of the cubic and hexagonal systems, respectively, are obtained. The four-dimensional classification of the levels of the spin-orbit interaction of rare earth ions for the intermediate reduction on the group of the four-dimensional cube is performed. With the help of the irreducible representations of the O ₄ group, the selection rules of magnetic and forbidden electric dipole transitions, as well as of intercombination transitions, are investigated.     

Hydrogenation of biphenyl and isomeric terphenyls over a Pt-containing catalyst

Catalytic hydrogenation of benzene, biphenyl, and ortho-, metha-, and para-isomers of terphenyl over a 3 wt.% Pt/C at 180 °C and 70 atm was studied. The directions of hydrogenation of each substrate were revealed. Relationships between structures of the substrate and hydrogen consumption rates were found. It was shown that hydrogenation rate decreases on going from benzene to terphenyl and with increasing degree of the substrate hydrogenation. Hydrogenation rate of terphenyl isomers decreases in the following order: p-terphenyl > > m-terphenyl > o-terphenyl.     

Thermochemistry of ethyl acetate solvation in the 1-octanol-N,N-dimethylformamide system

The thermal effects of ethyl acetate (EtOAc), 1-octanol (OctOH), and N,N-dimethylformamide (DMF) solution in a OctOH-DMF model system were measured using a calorimeter of variable temperature with an isothermal shell at 298 K. The standard enthalpies of solution and ester transfer from an alcohol to a binary mixture, and partial mole enthalpies of mixed solvent components were determined. The state of non-electrolyte molecules in OctOH-DMF and OctOH-DMF-EtOAc systems were studied using extended coordination model. It was found that the binary solvent is subjected to microclusterization, since the fraction of the single-type molecules in the solvation sphere of both components of a mixture is significantly higher than in the liquid phase volume. The conclusion was drawn that in the triple system, the ethyl acetate solvation sphere in the whole range of compositions is significantly enriched with amide owing to stronger esteramide dipole-dipole interaction.     

Ionic liquid [BMIM]PF6 as a medium for the selective hydrogenation of 1,4-diacetoxybut-2-yne on the Pd-containing catalysts

A possibility of using a ionic liquid, 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF₆), as a reaction medium in the liquid-phase hydrogenation of 1,4-diacetoxybut-2-yne was examined. Two types of catalysts were studied: Pd(10%)/C and the palladium-containing catalytic system based on the biopolymer chitosan supported on silica gel (Pd(1%)/chitosan/SiO2). The data obtained indicate high selectivity of hydrogenation of 1,4-diacetoxybut-2-yne to cis-1,4-diacetoxybut-2-ene under selected conditions.     

Temperature Hysteresis in CO Oxidation on Copper Oxide Catalyst Applied to a Steel Gauze

The temperature hysteresis during the heterogeneous catalysis was studied by an example of model reaction of CO oxidation on copper oxide catalyst applied to a stainless steel gauze.     

Cyclohexane transformations over metal oxide catalysts. 2. Selective cyclohexane ring opening to form n-hexane over mono- and bimetallic rhodium catalysts

The activity of monometallic Rh and Pt catalysts and bimetallic Pt—Rh catalysts on oxide supports in cyclohexane ring opening to form n-hexane was studied. The Rh-containing catalysts are highly active and selective in this reaction. Cyclohexane dehydrogenation predominates in the case of the Pt catalysts. The use of the bimetallic alumina-supported Pt—Rh catalysts allows one to minimize the contribution of cyclohexane cracking and to enhance the selectivity for n-hexane with the yield of the latter slightly depending on the metal ratio in the bimetallic system under the experimental conditions.     

Splash type mass transfer on the water film at downflow and upflow

Generation of droplets on a surface of the water thin film at upflow and down flow is considered. Expressions for computation of splash type mass transfer were developed.