Rare earth metal-rich indides RE 4IrIn ( RE = Gd–Er), RE 4IrInO0.25 ( RE = Gd, Er), and RE 4 T In1– x Mg x ( RE = Y, Gd; T = Rh, Ir)

The rare earth-transition metal-indides RE ₄IrIn (RE = Gd–Er) and the solid solutions RE ₄ TIn_1–x Mg _x (RE = Y, Gd; T = Rh, Ir) were prepared by arc-melting of the elements and subsequent annealing. The rare earth sesquioxides were used as oxygen source for the suboxides RE ₄IrInO_0.25 (RE = Gd, Er). Single crystals of the indides were grown via slowly cooling of the samples and they were investigated via X-ray powder diffraction and single crystal diffractometer data: Gd₄RhIn type, F [`4]\bar 4 3m, a = 1372.3(6) pm for Gd₄IrIn, a = 1365.3(6) pm for Tb₄IrIn, a = 1356.7(4) pm for Dy₄IrIn, a = 1353.9(4) pm for Ho₄IrIn, a = 1344.1(4) pm for Er₄IrIn, a = 1370.3(5) pm for Y₄RhIn_0.54Mg_0.46, a = 1375.6(5) pm for Gd₄IrIn_0.55Mg_0.45, a = 1373.0(3) pm for Gd₄IrInO_0.25, and a = 1345.1(4) pm for Er₄IrInO_0.25. The rhodium and iridium atoms have a trigonal prismatic rare earth coordination. Condensation of the RhRE ₆ and IrRE ₆ prisms leads to three-dimensional networks which leave voids that are filled by regular In₄ or mixed In_4–x Mg _x tetrahedra. The indium (magnesium) atoms have twelve nearest neighbors (3In(Mg) + 9RE) in icosahedral coordination. The rare earth atoms build up a three-dimensional, adamantane-like network of condensed, edge and face-sharing octahedra. For Gd₄IrInO_0.25 and Er₄IrInO_0.25 the RE1₆ octahedra are filled with oxygen. The crystal chemical peculiarities of these rare earth rich compounds are discussed.     

Rare earth metal-rich indides RE 4IrIn ( RE = Gd–Er), RE 4IrInO0.25 ( RE = Gd, Er), and RE 4 T In1– x Mg x ( RE = Y, Gd; T = Rh, Ir)

The rare earth-transition metal-indides RE ₄IrIn (RE = Gd–Er) and the solid solutions RE ₄ TIn_1–x Mg _x (RE = Y, Gd; T = Rh, Ir) were prepared by arc-melting of the elements and subsequent annealing. The rare earth sesquioxides were used as oxygen source for the suboxides RE ₄IrInO_0.25 (RE = Gd, Er). Single crystals of the indides were grown via slowly cooling of the samples and they were investigated via X-ray powder diffraction and single crystal diffractometer data: Gd₄RhIn type, F 3m, a = 1372.3(6) pm for Gd₄IrIn, a = 1365.3(6) pm for Tb₄IrIn, a = 1356.7(4) pm for Dy₄IrIn, a = 1353.9(4) pm for Ho₄IrIn, a = 1344.1(4) pm for Er₄IrIn, a = 1370.3(5) pm for Y₄RhIn_0.54Mg_0.46, a = 1375.6(5) pm for Gd₄IrIn_0.55Mg_0.45, a = 1373.0(3) pm for Gd₄IrInO_0.25, and a = 1345.1(4) pm for Er₄IrInO_0.25. The rhodium and iridium atoms have a trigonal prismatic rare earth coordination. Condensation of the RhRE ₆ and IrRE ₆ prisms leads to three-dimensional networks which leave voids that are filled by regular In₄ or mixed In_4–x Mg _x tetrahedra. The indium (magnesium) atoms have twelve nearest neighbors (3In(Mg) + 9RE) in icosahedral coordination. The rare earth atoms build up a three-dimensional, adamantane-like network of condensed, edge and face-sharing octahedra. For Gd₄IrInO_0.25 and Er₄IrInO_0.25 the RE1₆ octahedra are filled with oxygen. The crystal chemical peculiarities of these rare earth rich compounds are discussed. Correspondence: Rainer P?ttgen, Institut für Anorganische und Analytische Chemie, Westf?lische Wilhelms-Universit?t Münster, Germany.     

Synthesis, crystal structure and properties of a new heptamolybdate (NH4)6H2[Cu(C2O4)2(Mo7O24)] · 9H2O

An interesting heptamolybdate (NH₄)₆H₂[Cu(C₂O₄)₂(Mo₇O₂₄)] · 9H₂O (I) was prepared by convenational method in an aqueous solution and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, X-ray photoelectron spectroscopy and single-crystal X-ray diffraction. Crystal data for I: monoclinic, space group P2₁/m with a = 10.1460(5), b = 18.2616(9), c = 10.4994(5) ?, β = 94.3410(10)°, and Z = 2. X-ray structure analysis revealed the complexes to contain a copper center in an octahedral coordination mode bound to two [C₂O₄]²⁻ anios via the oxygen atoms and two oxygen atoms of the new heptamolybdate species. The zigzag chain structure of I is constructed by [Cu(C₂O₄)₂(Mo₇O₂₄)] units via Mo-O-Cu-O-Mo linkers.     

Decavanadates with complex cations: synthesis and structure of (NH4)2[M(H2O)5(NH3CH2CH2COO)]2V10O28·nH2O (M?=?ZnII, n?=?4; M?=?MnII, n?=?2)

Decavanadates with complex cations, (NH₄)₂[Zn(H₂O)₅(NH₃CH₂CH₂COO)]₂V₁₀O₂₈·4H₂O (4) and (NH₄)₂[Mn(H₂O)₅(NH₃CH₂CH₂COO)]₂V₁₀O₂₈·2H₂O (5), have been prepared and characterized by elemental analysis, i.r., Raman, UV–vis. and ⁵¹V-n.m.r. spectroscopies and by thermal analysis. The X-ray structure determination revealed, both in 4 and 5, the presence of complex cations with hexacoordinated central atoms and monodentate β-alanine ligands, and decavanadate V₁₀O₂₈ ⁶⁻ anions. The differences in the structural arrangement in 4 and 5 are probably a consequence of the different ionic radii of Zn²⁺ and Mn²⁺ (high spin).     

Solvothermal syntheses and crystal structures of two new thiogermanates [M(dap)3]4Ge4S10Cl4 (M?=?Co, Ni) with metal complexes as counterions

Abstract  

Two new transition-metal thiogermanates [M(dap)₃]₄Ge₄S₁₀Cl₄ (M = Co, Ni; dap = 1,2-propanediamine) have been solvothermally synthesized and structurally characterized. The two thiogermanates are isostructural and consist of discrete Ge₄S₁₀⁴⁻ adamantane-like ions, free Cl⁻ ions, and [M(dap)₃]²⁺ cations as counterions. The Ge₄S₁₀⁴⁻ anion is built from corner-sharing connection of four GeS₄⁴⁻ tetrahedra. Although some chalcogenidogermanates have been obtained by use of in situ generated transition-metal complexes as structure-directing agents under mild solvothermal conditions, their anions are usually dimeric [Ge₂Q₆]⁴⁻ (Q = S, Se) species. The new thiogermanates are rare examples of adamantane-like (Ge₄S₁₀⁴⁻) thiogermanates combined with transition-metal complexes. Their optical properties have been investigated by UV–Vis spectra.     

NASICON phases of variable composition K1? x A1? x R1+ x (MoO4)3 (0 ≤ x ≤ 0.2–0.6), where A = Ni, Mg, Co, or Mn and R = Yb, Lu, or Sc

Phases of variable composition K_1−x A_1−x R_1+x (MoO₄)₃) (0 ≤ x ≤ 0.2–0.6), where A = Ni, Mg, Co, or Mn and R = Yb, Lu, or Sc, which crystallize in a NASICON-type structure (space group R c) were synthesized by solid-phase reactions. Their crystal parameters were calculated, and IR and Raman spectra described. Original Russian Text ? N.M. Kozhevnikova, T.N. Khamaganova, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 5, pp. 864–865.     

The structure of a new octahedral fluoride complex of niobium (Me4N)2[Nb6F6Br6(H2O)2Cl4]·6H2O

The substitution reaction of thiocyanide groups of the complex K₄[Nb₆F₆Br₆(NCS)₆] in aqueous hydrochloric acid has afforded a new fluoride cluster anion [Nb₆F₆ ⁱ Br₆ ⁱ Cl₄ ^a (H₂O)₂ ^a ]²⁻ isolated as the salt (Me₄N)₂[Nb₆F₆Br₆Cl₄(H₂O)₂]·6H₂O (space group R3m, a = 11.230(5) ?, c = 26.230(5) ?, V = 2865(2) ?³, Z = 3, R1 = 0.0362, R2w = 0.0886). The anion contains the cluster core Nb₆F₆Br₆ having ordered “inner” ligands. Difference in the atomic radii of “inner” ligands causes a significant distortion of the metal cluster along the three-fold axis. Original Russian Text Copyright ? 2008 by N. G. Naumov, S. Cordier, C. Perrin, and S. B. Artemkina __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 6, pp. 1163–1166, November–December, 2008.     

A Raman spectroscopic study of the XeOF4/XeF2 system and the X-ray crystal structure of α-XeOF4·XeF2

The mixed oxidation state complexes, α-XeOF₄·XeF₂ and β-XeOF₄·XeF₂, result from the interaction of XeF₂ with excess XeOF₄. The X-ray crystal structure of the more stable α-phase shows that the XeF₂ molecules are symmetrically coordinated through their fluorine ligands to the Xe(VI) atoms of the XeOF₄ molecules which are, in turn, coordinated to four XeF₂ molecules. The high-temperature phase, β-XeOF₄·XeF₂, was identified by low-temperature Raman spectroscopy in admixture with α-XeOF₄·XeF₂; however, the instability of the β-phase precluded its isolation and characterization by single-crystal X-ray diffraction. The Raman spectrum of β-XeOF₄·XeF₂ indicates that the oxygen atom of XeOF₄ interacts less strongly with the XeF₂ molecules in its crystal lattice than in α-XeOF₄·XeF₂. The ¹⁹F and ¹²⁹Xe NMR spectra of XeF₂ in liquid XeOF₄ at −35 °C indicate that any intermolecular interactions that exist between XeF₂ and XeOF₄ are weak and labile on the NMR time scale. Quantum-chemical calculations at the B3LYP and PBE1PBE levels of theory were used to obtain the gas-phase geometries and vibrational frequencies as well as the NBO bond orders, valencies, and NPA charges for the model compounds, 2XeOF₄·XeF₂, and XeOF₄·4XeF₂, which provide approximations of the local XeF₂ and XeOF₄ environments in the crystal structure of α-XeOF₄·XeF₂. The assignments of the Raman spectra (−150 °C) of α- and β-XeOF₄·XeF₂ have been aided by the calculated vibrational frequencies for the model compounds. The fluorine bridge interactions in α- and β-XeOF₄·XeF₂ are among the weakest for known compounds in which XeF₂ functions as a ligand, whereas such fluorine bridge interactions are considerably weaker in β-XeOF₄·XeF₂.     

Crystal growth, crystal structure of new polymorphic modification, β-Bi2B8O15 and thermal expansion of α-Bi2B8O15

Single crystals of α- and β-polymorphs of Bi₂B₈O₁₅ were grown by Czochralski method from a charge of the stoichiometric composition. The crystal structure of β-Bi₂B₈O₁₅ was solved by direct methods from a twinned crystal and refined to R1=0.081 (wR=0.198) on the basis of 1584 unique observed reflections (I>2σ(I)). The compound is triclinic, space group , a=4.3159(8), b=6. 4604(12), c=22.485(4) Å, α=87.094(15)°, β=86.538(15)°, γ=74.420(14)°, V=602.40(19) Å³, Z=2. The B-O layered anion of β-Bi₂B₈O₁₅ is topologically identical to the anion of α-Bi₂B₈O₁₅ but the orientation of neighboring layers is different. Thermal expansion of α-Bi₂B₈O₁₅ has been investigated by X-ray powder diffraction in air in temperature range from 20 to 700 °C. It is strongly anisotropic, which can be explained by the hinge mechanism applied to chains of Bi-O polyhedra. While the anisotropy of thermal expansion is rather high, the volume thermal expansion coefficient α_V=40×10⁶ °C⁻¹ for α-Bi₂B₈O₁₅ is close to those of other bismuth borates.     

Synthesis and crystal structure of a new tetradecker complex: Tetra(μ4-N,N′-Ethylen-bis(3-Methoxysalicylideneamine)-bis(μ2-perchlorato-O,O′)-tetranickel(II)-tripotassium perchlorate

The title tetradecker complex C₇₂H₇₂Cl₃K₃N₈Ni₄O₂₈ has been synthesized and structurally characterized. The four NiL (L = N, N-ethylene-bis(3-methoxysalicylideneiminate) segments were linked into a discrete tetradecker structure by three K⁺ cation coordinated to the phenolic oxygen atoms of the neighboring NiL units and the oxygen atom of the ClO₄⁻ anions acting as bridges. The two bicephalous K⁺ cations are nine-coordinated, while the middle one is involved in a distorted bipentagonal pyramid. For the Ni²⁺ ion, it is involved in a square planar coordination sphere formed by a N₂O₂ unit from the Schiff base ligand.     

Subsolidus binary phase diagram of (n-CnH2n+1NH3)2ZnCl4 (n?=?14, 16, 18)

The thermotropic phase solid–solid transitions compound (n-C _n H_2n+1NH₃)₂ZnCl₄ (n = 14, 16, 18) were studied, and a series of their mixtures were prepared. These laminar materials contain bilayers sandwiched between metal halide layers. The low temperature crystal structures of the pure salts are characteristic of the piling of sandwiches in which a two-dimensional macro-anion ZnCl₄ ²⁻ is sandwiched between two alkylammonium layers. These layers become conformationally disordered in the high temperature phases. The subsolidus binary phase diagrams of (n-C₁₄H₂₉NH₃)₂ZnCl₄-(n-C₁₈H₃₇NH₃)₂ZnCl₄ and (n-C₁₆H₃₃NH₃)₂ZnCl₄-(n-C₁₈H₃₇NH₃)₂ZnCl₄ were established by differential thermal analysis and X-ray diffraction. In each phase diagram, an intermediate compound and two eutectoid invariants were observed. There are three noticeable solid solution ranges (α, β, γ) at the left boundary, right boundary, and middle of the phase diagram.     

Surface active and aggregation behavior of methylimidazolium-based ionic liquids of type [Cnmim] [X], n?=?4, 6, 8 and [X]?=?Cl?, Br?, and I? in water

The surface active and aggregation behavior of ionic liquids of type [C _n mim][X] (1-alkyl-3-methylimidazolium (mim) halides), where n = 4, 6, 8 and [X] = Cl⁻, Br⁻ and I⁻ was investigated by using three techniques: surface tension, ¹H nuclear magnetic resonance (NMR) spectroscopy, small-angle neutron scattering (SANS). A series of parameters including critical aggregation concentrations (CAC), surface active parameters and thermodynamic parameters of aggregation were calculated. The ¹H NMR chemical shifts and SANS measurements reveal no evidence of aggregates for the short-chain 1-butylmim halides in water and however small oblate ellipsoidal shaped aggregates are formed by ionic liquids with 1-hexyl and 1-octyl chains. Analysis of SANS data analysis at higher concentrations of [C₈mim][Cl] showed that the microstructures consist of cubically packed molecules probably through π–π and hydrogen bond interactions.     

Synthesis and crystal structure of the octahedral cyano-bridged cluster complex β-[{Ni(NH3)5}2{Re6Te8(CN)6}]·4H2O

The rhenium cyano-bridged cluster complex with a composition of β-[{Ni(NH₃)₅}₂{Re₆Te₈(CN)₆}]−4H₂O is obtained and structurally characterized. The compound pound crystallizes in the P $ P\bar 1 $ P\bar 1 triclinic space group with the unit cell parameters: a = 9.997(2) ?, b = 10.423(2) ?, c = 11.714(2) ?, α = 100.92(3)°, β = 111.87(3)°, γ = 98.05(3)°, V = 1082.1(4) ?³, Z = 1, d _calc = 4.072 g/cm³. The rhenium atoms of the {Re₆Te₈} cluster core are coordinated by CN ligands to form the [Re₆Te₈(CN)₆]⁴⁻ cluster; two nitrogen atoms of CN ligands trans-positioned with respect to each other are coordinated to Ni atoms in the {Ni(NH₃)₅}²⁺ fragments to form the molecular complexes of [{Ni(NH₃)₅}₂}Re₆Te₈(CN)₆}]. The crystal structure is the H-bonded packing of these molecular complexes and crystallization water molecules.     

Synthesis, crystal growth and structure of Mg containing β-rhombohedral boron: MgB17.4

For the first time, single crystals of Mg containing β-rhombohedral boron MgB_17.4 were synthesised from the elements in a Mg/Cu melt at 1600 °C. The crystal structure determined by the refinement of single crystal data (space group R-3m, , , 890 reflections, 123 variables, R₁(F)=0.049, wR₂(I)=0.122) improves and modifies the former structure model derived from earlier investigations on powder samples. Mg is located on four different positions with partial occupation. While the occupation of the sites D (53.3%), E (91%) and F (7.2%) is already known from other boron-rich borides related to β-rhombohedral boron, the occupation of the fourth position (18h, 6.7%) is observed for the first time. Two boron positions show partial occupation. The summation reveals the composition MgB_17.4 and Mg_5.85B_101.9, respectively, confirmed by WDX measurements. The single crystals of MgB_17.4 show the highest Mg content ever found. Preliminary measurements indicate no superconductivity.     

10 α -Hydroxy- β -isomorphine, a by-product of the synthesis of 10 α -hydroxymorphine

Abstract  

A new compound was isolated from the reaction mixture after O-demethylation of 6-O-acetyl-10α-acetoxycodeine with boron tribromide. The structure of this compound, 10α-hydroxy-β-isomorphine, was elucidated by spectral data, and its spatial arrangement was deduced from an NOE experiment. Capillary zone electrophoresis was used for separation of morphine and its 10-hydroxy analogues.     

Synthesis and study of the properties of K2Y1 ? x ? yEuxTby(MoO4)(PO4) and K2Y1 ? x ? yEuxTby(MoO4)(PO4)1?δ(VO4)δ solid solutions

Al synthesized samples are isostructural and crystallize in the orthorhombic symmetry system, space group Ibca. Particles of the final product of ∼200 nm in size have been obtained. The introduction of the vanadate anion into the matrix composition leads to the lowering of the symmetry of the Eu³⁺ environment and to the rise of the defect luminescence at 450–550 nm because of the unit cell distortion. The luminescence of defects in terbium-europium-containing samples is determined by the sample surface area, which decreases on annealing. The τ, W ₀ and γ parameters of the luminescence kinetics of the samples have been determined.     

Intermolecular cycloalumination of cyclic and acyclic alkynes with Et n AlCl3? n in the presence of Cp2ZrCl2

Intramolecular cycloalumination of cyclic and acyclic alkynes with Et _n AlCl_3−n (n = 0, 1) in the presence of Cp₂ZrCl₂ gave previously unknown unsaturated bi-and tricyclic organoaluminum compounds in up to 80% yield. Original Russian Text ? V.A. D’yakonov, L.F. Galimova, A.G. Ibragimov, U.M. Dzhemilev, 2008, published in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 9, pp. 1308–1312.     

Crystal structure of a new polymorphic modification of β-K2[Pd(NO3)4]

X-ray diffraction is applied to study a new crystalline modification of K₂[Pd(NO₃)₄]-β-K₂[Pd(NO₃)₄]. It is found that the phase is isostructural with Na₂[Pd(NO₃)₄] and Rb₂[Pd(NO₃)₄]. Square coordination of the Pd atom is formed by oxygen atoms of monodentately coordinated nitrate groups. Original Russian Text Copyright ? 2009 by S. P. Khranenko, I. A. Baidina, and S. A. Gromilov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 2, pp. 374–377, March–April, 2009.     

Synthesis, spectral and electrochemical study of coordination molecules Cu4OX6L4: 3-cyanopyridine Cu4OBrnCl(6?n)(3-CNpy)4 complexes

New 4-cyanopyridine halide and mixed-halide Cu₄OBr _n Cl_(6−n)(4-CNpy)₄ complexes (4-CNpy = 4-cyanopyridine, n = 0–6) were synthesised, characterised, and studied by infrared spectra, electronic spectra, and cyclic voltammetry. Infrared spectra revealed donor-acceptor vibrational couplings of the Cu₄O, Cu-Cl, and Cu-N stretching vibrations with the in-plane and out-of-plane pyridine ring vibrations. The infrared spectra, electronic spectra, and half-wave potentials correspond to a weak donor and a strong acceptor behaviour of the 4-cyanopyridine ligands and to π-back bonding, Cu(II)→pyridine rings. The results were compared with the related pyridine and 4-substituted pyridine complexes.     

Synthesis and molecular structures of the cobalt complexes (η4-C4Me4)Co(CO)2SnCl3, (η4-C4Me4)Co(CO)2(TeI2Ph), and (η4-C4Me4)Co(CO)2 (TeBrIPh) with the shortened Co-Sn and Co-Te bonds

The complex (η⁴-C₄Me₄)Co(CO)₂I (I) reacted with excess SnCl₂ in boiling THF to give, through replacement of the iodide ligand by the fragment SnCl₃, the mononuclear complex (η⁴-C₄Me₄)Co(CO)₂SnCl₃ (II) containing the Co-Sn bond (2.459(1) ?). In a reaction of complex I with phenyltellurenyl halides PhTeI and PhTeBr, an analogous insertion into the cobalt-iodine bond yielded (η⁻C₄Me₄)Co(CO)₂(TeI₂Ph) (III) and (η⁴-C₄Me₄)Co(CO)₂(TeBrIPh) (IV), respectively. This type of coordination of the aryltellurenyl halide fragment to the transition metal atom was observed for the first time. X-ray diffraction analysis revealed a substantial shortening of the formally single Co-Sn and Co-Te bonds in complexes II–IV compared to the sum of the covalent radii of the corresponding atoms. Original Russian Text ? Yu.V. Torubaev, A.A. Pasynskii, A.R. Galustyan, p. Mathur, 2009, published in Koordinatsionnaya Khimiya, 2009, vol. 35, No. 1, pp. 3–7.