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     

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     

Effects of specific interactions on the anisotropy of crystal structure distortion of [Co(NH3)5NO2]Cl2 under hydrostatic pressure

Using some special experimental techniques for anisotropic refinement of the crystal structure of [Co(NH₃)₅NO₂]Cl₂ at high pressures gave results with an accuracy comparable to that obtained in normal conditions. The anisotropy of lattice compression under pressure is determined by specific interactions in crystals, in particular, by NH-Cl and NH-O hydrogen bonds. The anisotropy of compression at increased pressure is qualitatively distinct from that caused by lowered temperature for the same structure. This difference is also due to specific interactions (hydrogen bonds) in the structure. Institute of Solid State Chemistry, Siberian Branch, Russian Academy of Sciences (Novosibirsk). Novosibirsk State University. Marburg University. Translated fromZhurnal Strukturnoi Khimii, Vol. 39, No. 3, pp. 433–447, May–June, 1998. This work was supported by A. Humboldt Foundation.     

Essential oil of Artemisia rubripes

Tomsk State Medical Institute. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 859–860, November–December, 1991.     

Structural instability of a crystal consisting of paramagnetic complexes,at a one-ion character of a spin-lattice coupling. A case of a quasiclassical limit

Novosibirsk Branch, Moscow Institute of Light Industry. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 4, pp. 76–81, July–August, 1982.     

Composition of the essential oil of Thymus krylovii

Tomsk State Medical Institute. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 886–887, November–December, 1988.     

Using intercalation compounds of aluminum hydroxide for syntheses of nanoscale systems

Routes for synthesizing intercalation compounds of aluminum hydroxide [M_xAl_y(OH)_z]_n X · pH₂O (M=Li, Mg, Ni, Co, …) are suggested, and application of these schemes to syntheses of nanoscale systems is examined. It is shown that nanoscale systems varying in composition, structure, and morphology may be obtained according to the nature of anion X and reaction conditions. Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences (Novosibirsk). Translated fromZhurnal Strukturnoi Khimii, Vol. 39, No. 3, pp. 453–459, May–June, 1998.     

Crystallochemical features of the anion varieties of aluminum and lithium binary hydroxide

Crystallochemical features of anion (Cl⁻, Br⁻, I⁻, NO ₃ ⁻ , CO ₃ ²⁻ , SO ₄ ²⁻ ) varieties of the aluminum and lithium hydroxide were studied by using the aluminum and lithium binary hydroxide (LiOH·2Al(OH)₃·2H₂O) model in space group P6₃cm with the tetrahedral coordination of lithium. Atomic coordinates corresponding to the lowered lattice symmetry were refined. Institute of Solid State Chemistry and Processing of Mineral Raw Materials, Siberian Branch, Russian Academy of Sciences. Novosibirsk State Pedagogical University. Translated fromZhurnal Struktumoi Khimii, Vol. 35, No. 5, pp. 158–170, September–October, 1994. Translated by T. Yudanova     

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     

Semiempirical andab initio study of the structure of the alumophenylsiloxane complex and its fragments

The structures, spectra, and electron density distributions of the alumophenylsiloxane (APS) complex and its fragments have been calculated using semiempirical (AM1) and ab initio (SCF/3-21G and SCF/6-31G^*) quantum chemical approximations. It has been shown that the local properties of the central fragment of alumophenylsiloxane, which is a slightly distorted tetrahedron AlO₄, are described with the (LiO)₂AlOBe(OH) cluster. M. V. Lomonosov Moscow State University. I. M. Gubkin State Academy of Oil and Gas. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 3, pp. 410–417, May–June, 1995. Translated by I. Izvekova     

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.     

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     

Data selection for structure generation in structure elucidation systems using molecular spectroscopy databases

Data selection techniques are considered for structure generation in structure elucidation systems using molecular spectroscopy databases. The starting data are sets of microfragments and connected structural fragments obtained from computer-aided analysis of mass, IR, and NMR spectra. Selection of fragments that do not isomorphically fit in larger fragments mostly leads to correct results with fewer output structures anddemands less computer time. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 2, pp. 46–53, March–April, 1994. Translated by L. Smolina     

Electronic structure and properties of the ground state of copper in semiconducting cuprates

The spin-polarized discrete variational X_a method is used to calculate clusters that model the electronic structures of CuO, La₂CuO₄, and Nd₂CuO₄. It, is shown that in each of the compounds the unoccupied portion of the valence band involves mainly the O2p states, the contributions from the Cu3d orbitals being significantly smaller. The effects of the nature of holes in the valence band and of the structure of the close environment of copper on the low-energy CuK spectra and the X-ray photoelectron spectra of the above systems are discussed. Institute of Solid State Chemistry, Ural Branch, Russian Academy of Sciences. Translated fromZhumal Struktumoi Khimii, Vol. 36, No. 4, pp. 636–643, July–August., 1995. Translated by I. Izvekova     

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.     

“Perfect” structure regions in amorphous argon

The structure of molecular dynamic models of amorphous argon is investigated by the Voronoi-Delaunay method. It is shown that the majority of Delaunay simplices (determined by quadruplets of the nearest atoms) are “perfect,” i.e., close in their shape either to the ideal tetrahedron or to the ideal quartoctahedron. These two types of structural elements are positioned in a correlated manner relative to each other, forming regions of a “perfect” structure which, however, is not crystalline. The regions themselves are separated by sections of an “imperfect” structure in which the shape of simplicial atomic configurations differs from the mentioned ideal forms. Institute of Chemical Kinetics and Combustion, Siberian Branch, Russian Academy of Sciences. Novosibirsk State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 1, pp. 53–63, January–February, 1994. Translated by L. Chernomorskaya     

Neutral extractive substances from the bark of Larix sibirica

Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 833–834, November–December, 1990.     

Acid succinates of diterpene alcohols — A new type of components of conifer oleoresins

Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 698–699, September–October, 1990.     

Structural data representation and search for structural analogs in molecular spectroscopy databases

A method for encoding structural formulas of organic compounds using two varieties of the tree code is suggested. The tree code is a sequence of symbols, each corresponding to an edge of a molecular graph traced around in width or in depth. The deep tree code provides compact storage of structural formulas and rapid substructure search. The wide tree code is a basis for a structure collection classifier providing quick access to structurally related compounds. Three techniques for selecting structural analogs of the compound using the classifier are proposed. Databases on mass and¹³C NMR spectra serve as illustrations. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 6, pp. 1129–1139, November–December, 1996. Translated by L. Smolina