X α-SW calculation of the XANES spectra of molybdenum in NiMoO4 and MoO3 crystals

Disadvantages of the modeling of the nearest crystal environment by a traditionally charged cluster for an atom with essentially covalent bonds are demonstrated by a comparison between the numerical and experimental XANES absorption spectra of molybdenum in NiMoO₄ and MoO₃. A model of boundary conditions is proposed, which allows adequate calculation of the covalent character of bonds in terms of the SCF-X_α-SW method. The oxygen environment of molybdenum in NiMoO₄ is determined. Institute of Solid State Chemistry and Processing of Minerals, Siberian Branch, Russian Academy of Sciences. Institute of Catalysis, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 6, pp. 1004–1011, November–December, 1995. Translated by I. Izvekova     

Structure and stability of the SiH3O2: Radical

A quantum chemical ab initio study of the electronic structure and force constants of the SiH₃O ₂ ^. radical is reported. The minimum on the potential surface corresponds to a C_s symmetry structure (the²A¹¹ term). The Hartree-Fock solution with the minimal energy for this structure does not satisfy the aufbau principle. The calculated enthalpy of SiH₃O ₂ ^. formation from SiH ₃ ^. and O₂(³∑_g ^-) is approximately −30 kcal/mole. Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Institute of Catalysis, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 1, pp. 25–30, January–February, 1994. Translated by L. Smolina     

Synthesis and investigation of the electronic structure of molybdenum tetrasulfide and its lithium intercalates

An X-ray amorphous phase of molybdenum tetrasulfide with the analytical formula MoS₄ has been sythesized. Quantum chemical modeling of the suggested local structure of MoS₄ and EHT calculation of the electronic structure of the basic (Mo₂S₄)⁴⁺ fragment are reported. The electronic structure of molybdenum tetrasulfide and its lithium intercalates was investigated by X-ray emission and X-ray photoelectron spectroscopy. It is shown that the change in the electronic structure of the starting molybdenum tetrasulfide to four lithium atoms per formula unit in the intercalate may be considered in the rigid band model. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 4, pp. 727–734, July–August, 1996. Translated by L. Smolina     

Coordinated diaminoguanidinium(1+) ion in the crystal structure of the [Cu(CH8N5)Cl3] complex

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Institute of Organoelement Compounds, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 5, pp. 936–941, September–October, 1995.     

Crystal and molecular structure of 1-(2′-methoxyphenyl)-3,7,10-trimethylstannatrane

A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences. Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 5, pp. 199–203, September–October, 1994.     

Paramagnetic nickel defect withC 3v symmetry in synthetic diamonds

Institute of Inorganic Chemistry, Siberian Branch Russian Academy of Sciences Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 4, pp. 138–141, July–August, 1994.     

Problems of using dynamic NMR techniques in studies of photoinduced molecular dynamics

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 4, pp. 753–756, July–August, 1995.     

Construction of crystal structure sections using the clat software package

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Institute of Physical Chemistry, Polish Academy of Sciences. Translated fromZhurnal Struktumoi Khimii, Vol. 36, No. 5, pp. 956–959, September–October, 1995.     

1H NMR in CaCl2·xH2O nanocrystals and water sorption isobars in a CaCl2-silica gel system

Mobility of water molecules in nanocrystals and other phases of CaCl₂·xH₂O (x=0–12) formed in the nanopores of silica gel during sorption of water vapor is studied by¹H NMR. The sorption properties of calcium chloride impregnated in the pores of micro- and mesoporous silica gels were measured. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. G. K. Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 39, No. 2, pp. 261–266, March–April, 1998. This work was supported by RFFR grants No. 96-03-33069 and 97-03-33533 and NATO grant HTECH LG N 970330.     

Evolution of OH-vibration bandshape in liquids upon hydrogen bond strengthening

Institute of Chemical Kinetics and Combustion, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 2, pp. 135–138, March–April, 1994.     

Magneto-structural correlations in layered polymeric molecular ferromagnets based on Ni(II) and Co(II) complexes with 3-imidazoline nitroxide radicals and methanol with different substituents in the metal cycle

We report on the synthesis, structure, and magnetic properties of Ni(II) and Co(II) complexes with deprotonated enaminoketone derivatives of 3-imidazoline nitroxide radicals and methanol, ML₂(CH₃OH)₂. The complexes differ in substituents in the γ-position of the donor enaminoketone group (Cl, H, CH₃). When the substituents are varied, the magnetic behavior of these exchange clusters and their capability for three-dimensional ordering of magnetic moments at 5–7 K are not altered, and the arrangement of polymer layers remains constant. However, such variation of substituents is very important for the chemistry of these compounds. Thus the accepting ability of the central atom is reduced by substitution of the hydrogen atom by the methyl group but enhanced by substitution of halogen for hydrogen in the side chain of the enaminoketone. This favors a magnetic phase transition to a ferromagnetic state. The results obtained in this work are important for the chemical design of molecular ferromagnets based on metal bischelates with paramagnetic ligands. International Tomography Center, Siberian Branch, Russian Academy of Sciences. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Novosibirsk State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 4, pp. 76–90, July–August, 1994. Translated by L. Smolina     

Isomerization kinetics of carbon clusters 1. Potential of interatomic interaction

Formation of fullerenes — spherical carbon clusters C₆₀ and clusters of other sizes — during condensation of carbon vapors has not yet received theoretical explanation. Recent experimental works concerned with cluster formation in carbon vapors have established that during condensation carbon atoms form rings and then polycyclic clusters, which are precursors of fullerenes. Theoretical investigation of the spontaneous formation of fullerenes from polycyclic rings calls for a simple model of the potential of interatomic interaction of carbon, which would allow fast calculations of bond energies and statistical sums of the clusters. We use the modified Brenner potential, which was developed for hydrocarbon molecules. The parameters of the potential are refitted according to the results of quantum chemical calculations. Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences. Institute of Computation Technologies, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Struktumoi Khimii, Vol. 37, No.4, pp. 664–670, July–August, 1996. Translated by I. Izvekova     

Calculation of cohesive and mixing energies and equilibrium parameters of solid alkaline earth fluoride solutions

Institute of Chemistry and Chemical Metallurgical Processes, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 2, pp. 131–135, March–April, 1994.     

MNDO calculations of the electronic structure of lead β-diketonates

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturmoi Khimii, Vol. 35, No. 6, pp. 186–190, November–December, 1994.     

IR spectral study of SO2 adsorption on polysiloxane layers containing tertiary amino groups

Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 1, pp. 164–167, January–February, 1996.     

Fluorine magnetic shielding parameters in the [TiF6]2− octahedral anion

Magnetic shielding tensors of fluorine nuclei in the [TiF₆]²⁻ octahedral anion were measured by¹⁹F NMR. Representative experimental data show them to be independent of the crystal environment of the anion. L. A. Kirenskii Institute of Physics, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 4, pp. 68–75, July–August, 1994. Translated by L. Smolina     

X-ray diffraction study of polycrystals and films of lead (II) hexafluoroacetyl acetonate and pivaloyltrifluoroacetyl acetonate

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturmoi Khimii, Vol. 35, No. 3, pp. 136–140, May–June, 1994.     

Crystal and molecular structure of lead(II) pivalyl trifluoroacetonate

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 6, pp. 197–201, November–December, 1994.     

Synthesis and x-ray diffraction study of rhodium and iridium hexanitrite plumbates

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 1, pp. 141–143, January–February, 1994.     

Crystal structure of bis(5,5-dimethyl-1-hydroxo-4-oxo-2-phenyl-pyrrolin-2-YL-3), recyclization product of 3-imidazoline enaminoketone

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 3, pp. 145–151, May–June 1994.