Characteristics of the molecular structure of n-trimethylsilyl-2,4,6-tri-tert-butylphenylamidochlorophosphites

Institute of Organic Chemistry, Ukrainian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 5, pp. 109–115, September–October, 1992.     

X-Ray Diffraction Analysis and Luminescent Study of the Structure of the Tb2(CF3COO)6(H2O)6 Dimer Obtained from Terbium(III) Carbonate

The molecular and crystal structure of the terbium(III) trifluoroacetate trihydrate dimer synthesized from terbium(III) carbonate was studied by X-ray diffraction (XRD) analysis. Luminescent data unambiguously show that the compound is one of the isomers of Tb₂(CF₃COO)₆(H₂O)₆ composition. Evidence has been found for the presence of another isomer in the terbium(III) dimer obtained from terbium(III) hydroxide.     

Investigations in the xanthine series and among its condensed derivatives

A method has been developed for obtaining derivatives of 8-methyl-2,3-dihydro-6H-imidazo[1,2-f]xanthine. It has been established that 2,3-dihydroimidazo[1,2-f]-xanthines alkylate in position 6 of the uracil fragment. A method has been developed for obtaining derivatives of 2,3-dihydroimidazo[1,2-f]purin-7-one. The structure of the compounds synthesized have been confirmed by IR and PMR spectroscopy. Zaporozh'e Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 623–626, September–October, 1980.     

Aminoguanidinium cations and the square-bipyramidal hexachlorocuprate(II) anion in the (CH8N4)2[CuCl6] crystal structure

Synthesis and structure of a novel thermochromic complex (CH₈N₄)₂[CuCl₆] are reported. X-ray analysis of the compound was carried out for a single crystal 0.4×0.2×0.05 mm in size (a bright-yellow plate). The monoclinic unit cell parameters are a=7.167(1), b=15.561(3), c=7.328(1) Å, β=118.73(3)°, V=716.7(2) ų, space group P2₁, Z=2 (CH₈N₄)₂[CuCl₆] d_calc=1.99 g/cm³, μ(MoK_α)=2.65 mm^?1, R=0.0264, and R_w=0.0290 for 1411 I_hkl>2σ_I.     

Unusual Polymers Containing Alternating <Emphasis Type="Italic">s</Emphasis> and <Emphasis Type="Italic">d</Emphasis> Elements Connected by Bridging Pivalate

From tetrahydrofurane solutions containing Cu(II) or Co(II) and potassium pivalate (KPiv) (molar ratios Cu/K=1/10, Co/K=1/5) one can isolate polynuclear [K₃Co₂Piv₇(THF)₃] (1) and [K₆Cu₂Piv₁₀(HPiv)(THF)(H₂O)₂]\(\cdot\)2THF (2), respectively. In the solid state the structures of the compounds consist of alternating, oppositely winding helices with a step of 46.085 Å for 1 and 25.260 Å for 2. In 2, the bridging pivalates link the infinite helices into layers. For both compounds, an important peculiarity of the structure is wide separation of transition metal ions (at least 5.327 Å for 1 and 6.791 Å for 2). Due to the presence of excess KPiv in the reaction system, the Cu(II) and Co(II) ions do not “coalesce” into polynuclear complexes typically observed in transition metal pivalates; instead they form unusual polymer systems containing alternating atoms of s and d elements. For transition metal pivalates, this type of structure was found for the first time.     

Copper(II) Complexes with N-(3-Hydroximino-2-methylbutan-2-yl)methylamine (HL): Synthesis and Properties. Crystal and Molecular Structures of [Cu(HL)Cl2] and [Cu(HL)(H2O)2SO4]n

Paramagnetic copper(II) complexes with N-(3-hydroximino-2-methylbutan-2-yl)methylamine (HL), namely, Cu(HL)Cl₂(I), Cu(HL)(SO₄) · 2H₂O (II), and Cu(HL)(NO₃)₂(III), were obtained. The crystal structures of I and II were determined. The blue crystals of these compounds are monoclinic. For I(C₆H₁₄Cl₂CuN₂O): a = 8.820(1) Å, b = 6.511(1) Å, c = 18.255(2) Å, = 92.86(1)° V = 1047.0(2) ų, space group P2₁/c, _calcd = 1.679 g/cm³, Z = 4 for R ₁ = 0.0250; for II(C₆H₁₈CuN₂O₇S): a = 9.999(2) Å, b = 9.927(2) Å, c = 12.963(3) Å, = 106.37(3)°, V = 1234.5(4) ų, space group P2₁/c, _calcd = 1.753 g/cm³, Z = 4 for R ₁ = 0.0324. Crystals of I have a molecular structure. The Cu coordination polyhedron is a square bipyramid (2N + 2Cl + Cl + Cl) due to additional contacts with two Cl atoms from the neighboring molecules. Structure II is built from polymeric chains. The environment of the Cu atom is a distorted cis-octahedron (2N + 2O(H₂O) + 2O(SO₄)). Complexes I–IIIare characterized by IR and EPR spectroscopy.     

Dynamics of solutions of the simplest nonlinear boundary-value problems

We investigate two classes of essentially nonlinear boundary-value problems by using methods of the theory of dynamical systems and two special metrics. We prove that, for boundary-value problems of both these classes, all solutions tend (in the first metric) to upper semicontinuous functions and, under sufficiently general conditions, the asymptotic behavior of almost every solution can be described (by using the second metric) by a certain stochastic process. Institute of Mathematics, Ukrainian Academy of Sciences, Kiev. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 51, No. 6, pp. 810–826, June, 1999.     

Unique [(1)infinityNi(8)Bi(8)S] metallic wires in a novel quasi-1D compound. Synthesis, crystal and electronic structure, and properties of Ni(8)Bi(8)SI.

A new quasi-one-dimensional compound Ni(8)Bi(8)SI has been synthesized and its crystal structure determined from single-crystal X-ray diffraction data. The structure of Ni(8)Bi(8)SI consists of [(1)infinityNi(8)Bi(8)S] columns separated by iodine atoms. Conductivity and magnetic susceptibility measurements (down to 4.2 K) show that Ni(8)Bi(8)SI is a one-dimensional metal and exhibits Pauli paramagnetic properties. These observations are in good agreement with the results from electronic structure calculations. An analysis of the chemical bonding employing difference electron charge density maps reveals strong multicenter Ni-Bi bonds and pair Ni-S interactions within the [(1)infinityNi(8)Bi(8)S] columns. Only electrostatic interactions are inferred between the columns and iodine atoms.     

Molecular structure of P-Methoxy-C,C-Bis(Trimethylsilyl)Methylene-N-(2,4,6-Tri-Tert-Butylphenly)Imino-σ3λ5-Phosphorane

Institute of Organic Chemistry, Ukrainian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 5, pp. 158–160, September–October, 1992.