Geometry of the oxygen environment of molybdenum in NiMoO4 crystals

XANES and EXAFS data for molybdenum in NiMoO₄, Na₂MoO₄(2H₂O), and MoO₃ crystals are reported. Analysis of this information and the results of numerical simulations suggest the octahedral oxygen environment of molybdenum in NiMoO₄. 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. 998–1003, November–December, 1995. Translated by I. Izvekova     

Ab initio calculations of interaction between the hydrated Fe2+ ion and molecular ozone

The ab initio LCAO-MO-SCF method with the STO-3G basis set is employed to calculate the electronic structure of different hydrated Fe²⁺ complexes. The general scheme of the interaction of ozone with Fe²⁺ (aq) is considered, whose first stage involves formation of an intermediate of the type of the ferryl ion FeO²⁺. Institute of Catalysis, Siberian Branch, Russian Academy of Sciences. Ruberzhansk Branch of Dnepropetrovsk Chemical-Technological Institute. Translated fromZhurnal Struktumoi Khimii, Vol. 35, No. 2, pp. 32–39, March–April, 1994. Translated by O. Kharlamova     

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.     

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     

2H-imidazole-N-oxides as spin traps

The capacity of 2H-imidazole-1-oxides, which contain an aldonitrone group, for spin capture was investigated. The parameters of spin adducts with^.OH,^.CH₃, and^.CH₂OH radicals are reported.Institute of Chemical Kinetics and Combustion, Siberian Branch, Russian Academy of Sciences. Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1064–1068, May, 1992.     

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     

Comparative study of the electronic structure of Bi-Systems 2212

The electronic structure of conducting and nonconducting forms of Bi₂Sr₂CaCu₂O_8+x ceramics was investigated by X-ray and X-ray photoelectron spectroscopy. The conducting form differs in structure from the nonconducting one by the presence of oxygen and bismuth atoms in two oxidation states as well as by pd-hybridization of O2p- and Cu3d-electrons in the valence band. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhumal Struktumoi Khimii, Vol. 36, No. 1, pp. 108–111, January–February, 1995. Translated by L. Smolina     

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     

Production of (+)-norsolanadione

Institute of Chemistry, Bashkir Scientific Center, Urals Branch, Russian Academy of Sciences, Ufa. Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 735–736, September–October, 1991.     

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.     

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.     

Structural mechanism of selective binding of lithium on a solid matrix of Al(OH)3 from aqueous solutions

The structure of intercalation complexes of aluminum hydroxide with lithium salts is investigated by X-ray diffractometry and by²¹Al,⁷Li, and¹H NMR. The lithium ions occupy vacant positions in the octahedral voids of aluminum hydroxide, and all atoms of gibbsite change localization. Parameters of the²⁷Al and⁷Li quadrupole and¹H dipole-dipole interaction tensors in anhydrous and aqueous intercalates of gibbsite with lithium salts are determined. A mechanism is suggested for the interaction of gibbsite with aqueous solutions of lithium salts. Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences (Novosibirsk). Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences (Novosibirsk). Translated fromZhurnal Strukturnoi Khimii, Vol. 39, No. 3, pp. 448–452, May–June, 1998. This work was supported by RFFR grant No. 96-03-33069.     

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 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.     

X-ray photoelectron study of the state of Ba atoms in YBa2Cu3O7−δ doped with Co and Zn atoms

Investigating changes in the charged state of atoms upon superconductivity-suppressing substitutions is one of the methods to examine a relationship between the electronic structure of HTSC materials and the transition temperature to the superconducting state. In this paper, we measured E_bnd of the inner levels of Ba atoms in Co- and Zn-doped YBa₂Cu₃O_7−δ by X-ray photoelectron spectroscopy. Upon copper substitution by Co and Zn atoms, E_bnd of the inner levels diminishes for Ba atoms but remains the same for Cu and O atoms. The change of E_bnd of the inner levels of Ba atoms is attributed to the change of the Fermi level position in the “anionic” sublattice of (Cu₃O_7−δ)⁷⁻. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 4, pp. 91–95, July–August, 1994. Translated by L. Smolina     

Transformations of terpenoids on synthetic zeolites I. Reactions of labdane alcohols on zeolite HY

The transformations on zeolite HY of epimanool and of 13-hydroxylabd-8(17),14-dien-6-one and its Δ^7,8 isomer have been studied. Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 657–667, September–October, 1991.     

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.     

Exchange parameters of five-spin clusters of Cu(II) coordination compounds with imidazoline nitroxide radicals

The exchange Heisenberg interaction parameters have been determined from theoretical analysis of the temperature dependence of magnetic susceptibility of coordination cluster compounds [Cu(hfacac)₂]₃(Li⁽ⁱ⁾)₂ (hfacac is hexafluoroacetylacetonate, L⁽ⁱ⁾ are 3-imidazoline nitroxides). Upon coordination of both N O oxygens and heterocycle N(3) atoms by Cu²⁺ ions, the interactions are ferromagnetic in nature and have the same order of magnitude. The minor intercluster interactions are antiferromagnetic.Institute of Chemical Kinetics and Combustion, Siberian Branch, Russian Academy of Sciences. International Tomography Center. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 3, pp. 70–74, May–June 1993.Translated by L. Smolina     

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.