Synthesis and crystal structure of [Th2(μ-SO4)2(DMSO)12]{[Mo3S7Br5(DMSO)]Br}2·2DMSO·PhCN

Crystallization from a ThBr₄/DMSO/(Et₄N)₂Mo₃S₇Br₆ mixture in benzonitrile gave [Th₂(µ-SO₄)₂×(DMSO)₁₂]{[Mo₃S₇Br₅(DMSO)]Br}₂·2DMSO·PhCN. The complex has an ionic structure. In the [Th₂(µ-SO₄)₂(DMSO)₁₂]⁴⁺ centrosymmetric binuclear cation, the metal atoms are bound by two sulfate bridges and are coordinated by DMSO oxygen atoms, the coordination polyhedron of thorium(IV) being a tricapped trigonal prism (c.n. 9). The [Mo₃S₇Br₅(DMSO)]^–cluster anion and the bromide ion form an ion pair with S_ax...Br^– short contacts, and the DMSO molecule is coordinated to one of the molybdenum atoms via the oxygen atom. The voids of the structure are filled with DMSO and PhCN solvate molecules, the latter being disordered over two positions related by an inversion center.Original Russian Text Copyright © 2004 by M. N. Sokolov, O. A. Gerasko, S. F. Solodovnikov, and V. P. FedinTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 516–521, May–June 2004.     

Synthesis and crystal structure of gallosilicate- and aluminogermanate tetrahydroborate sodalites Na8[GaSiO4]6(BH4)2 and Na8[AlGeO4]6(BH4)2

Tetrahydroborate enclathrated sodalites with gallosilicate and aluminogermanate host framework were synthesized under mild hydrothermal conditions and characterized by X-ray powder diffraction and IR spectroscopy. Crystal structures were refined in the space group P-43n from X-ray powder data using the Rietveld method. Na₈[GaSiO₄]₆(BH₄)₂: a=895.90(1) pm, V=0.71909(3)×10⁻⁶ nm³, R_P=0.074, R_B=0.022, Na₈[AlGeO₄]₆(BH₄)₂: a=905.89(2) pm, V=0.74340(6)×10⁻⁶ nm³, R_P=0.082, R_B=0.026. The tetrahedral framework T-atoms are completely ordered in each case and the boron atoms are located at the centre of the sodalite cages. The hydrogen atoms of the enclathrated anions were refined on x, x, x positions, restraining them to boron-hydrogen distances of 116.8 pm as found in NaBD₄.The IR-absorption spectra of the novel phases show the typical bands of the tetrahedral group as found in the spectrum of pure sodium boron hydride.The new sodalites are discussed as interesting -containing model compounds which could release pure hydrogen.     

Lanthanide (III) addition of [Mo2O3S(HNTA)2] (Ln=Eu, Dy)

The reactions of LnCl₃·6H₂O (Ln=Eu or Dy) and Na₂[Mo₂O₃S(HNTA)₂]·6H₂O afford Na[Mo₂O₃S(HNTA)₂]₂·Eu(H₂O)₉·3H₂O (1) (NTA=nitrilotriacetate) and Na{(H₂O)₆Dy[Mo₂O₃S(HNTA)₂]₂}·7.5H₂O (2), respectively. The [Mo₂O₃S(HNTA)₂]²⁻ cluster units of 1 are interconnected by Na⁺ into a 3-D open framework with rutile topology templated by . The coordination of [Mo₂O₃S(HNTA)₂]²⁻ to the slightly smaller Dy³⁺ ion of greater ionic potential as a consequence of lanthanide contraction has been observed to form the pentanuclear heterometallic {Dy(H₂O)₆[Mo₂O₃S(HNTA)₂]₂}⁻, which is linked by Na⁺ and hydrogen bonds between the protonated carboxylate groups into a 3-D supramolecular framework. The weak antiferromagnetic interactions between the Dy³⁺ ions of 2 have been observed.     

Photochemical reaction of W(CO)6 with SnCl4 II. Synthesis and X-ray structure of tetrachlorobis(triphenylphosphine oxide)tungsten(IV), [WCl4(OPPh3)2]

The crystal structure of [WCl₄(OPPh₃)₂](1), formed in the photochemical reaction of W(CO)₆ with SnCl₄ in the presence of triphenylphosphine, has been determined by the single-crystal X-ray diffraction method. The compound crystallizes in the monoclinic space C2/c, with A=14.027(3), B=13.163(3), C=19.621(4) Å, β=96.36(3)°, Z=4. The structure solved by heavy-atom methods has been refined to R=0.0466, for 3489 observed reflections.

The [WCl₄(OPPh₃)₂] molecule possesses a crystallographically imposed C₂ axis passing through the tungsten atom. Despite steric demands, a mutually cis arrangement of triphenylphosphine oxide oxygens is found for [WCl₄(OPPh₃)₂], while there is a slight lengthening of the W---Cl bonds trans to the oxygen atoms.     

Unprecedented μ3-O face-capping ligand in a [Mo6Br6L2Br6] (L = 0.5 O + 0.5 Br) molybdenum cluster unit: crystal structure of the Cs3Mo6Br13O oxybromide

The new Cs₃Mo₆Br₁₃O oxybromide, synthesized by solid-state chemistry, crystallizes in the trigonal system (Rc space group; a = 15.5784(2) Å, c = 19.5103(5) Å, V = 4100.5(1) Å³ and Z = 6). It is based on a [Mo₆L₁₄] unit that contains an unprecedented μ₃ face-capping oxygen. The crystal structure determined by single crystal X-ray diffraction is built up from discrete face-capped [Mo₆Brⁱ₆Lⁱ₂Br^a₆]^3– (L = 0.5 O + 0.5 Br) anionic units in which two inner positions are randomly occupied by one bromine and one oxygen whereas the other ligand positions are fully occupied by bromine. The cesium cations randomly occupy two close crystallographic positions generated by the A-B-C-A′-B′-C′ close-packed stacking of the units. The cesium site occupancy is related to the random distribution of oxygen and bromine on the Lⁱ inner positions. To cite this article: K. Kirakci et al., C. R. Chimie 8 (2005).     

Synthesis, crystal structure, spectroscopic and thermal properties of [Et4N][Ta6Br12(H2O)6]Br4·4H2O (Et=ethyl)—A new compound with the paramagnetic [Ta6Br12] cluster core

A new hexanuclear cluster compound, [Et₄N][Ta₆Br₁₂(H₂O)₆]Br₄·4H₂O (Et=ethyl) (1), with the paramagnetic [Ta₆Br₁₂]³⁺ cluster entity, was synthesized and characterized by elemental and TG/DTA analyses, IR and UV/Vis spectroscopy and by a single-crystal X-ray diffraction study. The presence of the paramagnetic [Ta₆Br₁₂]³⁺ unit was confirmed also by the room-temperature magnetic and EPR measurements. The compound crystallizes in the tetragonal I4₁/a space group, with a=14.299(5), c=21.241(5) Å, Z=4, R₁(F)/wR₂(F²)=0.0296/0.0811. The structure contains discrete [Ta₆Br₁₂(H₂O)₆]³⁺ cations with an octahedron of metal atoms edge-bridged by bromine atoms and with water molecules occupying all six terminal positions. The cluster units are positioned in the vertices of the three-dimensional (pseudo)diamond lattice. The structure shows similarities with literature reported structures of cluster compounds crystallizing in the diamond space group.     

Synthesis and structures of new niobium cluster compounds with pyridinium cations: (PyrH)2[Nb6Cl18]·EtOH (Pyr: pyridine, Et: ethyl) and the cubic modification of (PyrH)2[Nb6Cl18]

Slow crystallization of (PyrH)₂[Nb₆Cl₁₈] from hot ethanol solution affords triclinic (PyrH)₂[Nb₆Cl₁₈]·EtOH. Treatment of [Nb₆Cl₁₄(H₂O)₄]·4H₂O with pyridine in a methanol solution gives the second title compound, the cubic modification of (PyrH)₂[Nb₆Cl₁₈]. Both structures were determined by single crystal X-ray diffraction, (PyrH)₂[Nb₆Cl₁₈]·EtOH: P1¯, a=9.3475(3), b=9.3957(3), c=10.8600(3) Å, α=82.582(1)°, β=78.608(1)°, and γ=78.085(1)°, Z=1, R₁(F)/wR₂(F²)=0.0254/0.0573, cub.-(PyrH)₂[Nb₆Cl₁₈]: Fd3¯m, a=19.935(2) Å, Z=8, R₁(F)/wR₂(F²)=0.0557/0.1796. The cluster compounds contain isolated, molecular [Nb₆Clⁱ₁₂Cl^a₆]²⁻ cluster anions with an octahedron of metal atoms edge bridged by chlorido ligands with additional ones on all the six exo positions. These cluster anions are separated by the pyridinium cations and ethanol solvent molecules, respectively. For the cubic modification of (PyrH)₂[Nb₆Cl₁₈], a structural comparison is given to the known rhombohedral modification using the group-subgroup relations as expressed by a Bärnighausen tree.     

Synthesis and structure of a novel complex [LCo(OH)2(HCO3)CoL]2[(NC)5Cr(CN)Cr(CN)2].4H2O

A novel complex containing a (μ-bicarbonato)-bis(μ-hydroxo)dicobalt(II) cation and a (μ-cyano)dichromium(III) anion has been obtained and characterized by single crystal X-ray diffraction. The cations have a confacial bioctahedral structure and the anion contains an octahedral Cr(CN)₆³⁻ unit bridging to the second Cr which has trigomal planar geometry.     

A crystal structure of mixed-metal dianionic phosphate Cs3.70Mg0.60Ti2.78(TiO)3(P2O7)4(PO4)2

The single crystals of caesium magnesium titanium (IV) tri-oxo-tetrakis-diphosphate bis-monophosphate, Cs_3.70Mg_0.60Ti_2.78(TiO)₃(P₂O₇)₄(PO₄)₂, crystallize in sp. gr. P-1 (No. 2) with cell parameters a=6.3245(4), b=9.5470(4), c=15.1892(9) Å, α=72.760(4), β=85.689(5), γ=73.717(4), z=1. The titled compound possesses a three-dimensional tunnel structure built by the corner-sharing of distorted [TiO₆] octahedra, [Ti₂O₁₁] bioctahedra, [PO₄] monophosphate and [P₂O₇] pyrophosphate groups. The Cs⁺ cations are located in the tunnels. The partial substitution of Ti positions with Mg atoms is observed. The negative charge of the framework is balanced by Cs cations and Mg atoms leading to pronounced concurrency and orientation disorder in the [P₂O₇] groups, which coordinate both.     

Structural and conductivity studies of CsKSO4Te(OH)6 and Rb1.25K0.75SO4Te(OH)6 materials

The crystal structures of the title compounds were solved using the single-crystal X-ray diffraction technique. At room temperature CsKSO₄Te(OH)₆ was found to crystallize in the monoclinic system with Pn space group and lattice parameters: ; ; ; β=106.53(2)°; ; Z=4 and . The structural refinement has led to a reliability factor of R₁=0.0284 (wR₂=0.064) for 7577 independent reflections. Rb_1.25K_0.75SO₄Te(OH)₆ material possesses a monoclinic structure with space group P2₁/a and cell parameters: ; ; ; β=106.860(10)°; ; Z=4 and . The residuals are R₁=0.0297 and wR₂=0.0776 for 3336 independent reflections. The main interest of these structures is the presence of two different and independent anionic groups (TeO₆⁶⁻ and SO₄²⁻) in the same crystal.Complex impedance measurements (Z^*=Z^′—iZ^″) have been undertaken in the frequency and temperature ranges 20-10⁶ Hz and 400-600 K, respectively. The dielectric relaxation is studied in the complex modulus formalism M^*.     

Synthesis and characterisation of the methylene-inserted mixed-chalcogenide compounds Fe2(CO)6(μ-SeCH2Te) and Fe2(CO)6(μ-SCH2Te)

The methylene-bridged, mixed-chalogen compounds Fe₂(CO)₆(μ-SeCH₂Te) (1) and Fe₂(CO)₆(μ-SCH₂Te) (3) have been synthesised from the room temperature reaction of diazomethane with Fe₂(CO)₆(μ-SeTe) and Fe₂(CO)₆(μ-STe), respectively. Compounds 1 and 3 have been characterised by IR, ¹H, ¹³C, ⁷⁷Se and ¹²⁵Te NMR spectroscopy. The structure of 1 has been elucidated by X-ray crystallography. The crystalsare monoclinic,space group P2₁/n, A = 6.695(2), B = 13.993(5), C = 14.007(4)Å, β = 103.03(2)°, V = 1278(7) ų, Z = 4, D_c = 2.599 g cm⁻³ and R = 0.030 (R_w = 0.047).     

Synthesis and structure of diethyltindichloride methylenediphosphinato complex: Et2SnCl2 · [Me( PrO)P(O)]2CH2

In the title complex the disphosphinato ligand coordinates in a chelate mode to give a distorted octahedral environment at tin with the ethyl groups in a trans position.     

An extended open framework based on disordered [Nb6Cl9O3(CN)6] cluster units: Synthesis and crystal structure of Cs3Mn[Nb6Cl9O3(CN)6]0.6H2O

The synthesis and crystal structure of Cs₃Mn[Nb₆Cl₉O₃(CN)₆]0.6H₂O are described in this work. It crystallizes in the cubic system (space group Fm-3m; a=15.708(5) Å) and is characterized by a static orientational disorder of the [Nb₆Cl₉O₃(CN)₆]⁵⁻ cluster units. It results in a framework structurally related to that encountered in the well known Prussian Blue family prepared for different hexacyanometallates. The charge of the framework is compensated by cesium cations that are located in the tetrahedral cavities of the c.f.c. lattice of units along with water molecules. We will evidence the features that act in the crystallization of solid state compounds built up from ordered or disordered units as well as the influence of orientational disorder on interatomic distances obtained from single-crystal X-ray diffraction investigations.     

Investigation of phase transitions of a pseudo-hexagonal phase of [Rh(NH3)5Cl]2[Re6S8(CN)6]·3H2O during thermal decomposition

A general motif of the crystal structure of [Rh(NH₃)₅Cl]₂[Re₆S₈(CN)₆]·3H₂O is examined, and the cluster anions are found to form a pseudo-hexagonal sublattice. The thermal decomposition of [Rh(NH₃)₅Cl]₂[Re₆S₈(CN)₆]·3H₂O is studied, and it is shown that in helium atmosphere thermolysis occurs through the formation of intermediate amorphous phases. The final product obtained at 1200°C is a disordered single-phase solid solution of Re_0.75Rh_0.25 based on the structure of rhenium. Powder X-ray diffraction data for solid solutions in the system of Rh-Re are surveyed. It is demonstrated that the data for phases prepared by the thermal decomposition of coordination compounds better match the theoretical state diagram than the experimental one. The dependence of atomic volume on the composition of solid solutions of Re_xRh_1−x is derived. Original Russian Text Copyright ? 2007 by S. A. Gromilov, K. V. Yusenko, and E. A. Shusharina __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No.5, pp.957–962, September–October, 2007.     

Mixed-metal cluster chemistry VI: Phosphine substitution at CpMoIr3(μ-CO)3(CO)8; X-ray crystal structure of CpMoIr3(μ-CO)3(CO)7(PPh3)

Reactions of CpMoIr₃(μ-CO)₃(CO)₈ (1) with stoichiometric amounts of phosphines afford the substitution products CpMoIr₃(μ-CO)₃(CO)_8−x (L)_x (L = PPh₃, x = 1 (2), 2 (3); L = PMe₃, x = 1 (4), 2 (5), 3 (6)) in fair to good yields (23–54%); the yields of both 3 and 6 are increased on reacting 1 with excess phosphine. Products 2–5 are fluxional in solution, with the interconverting isomers resolvable at low temperatures. A structural study of one isomer of 2 reveals that the three edges of an MoIr₂ face of the tetrahedral core are spanned by bridging carbonyls, and that the iridium-bound triphenyiphosphine ligates radially and the molybdenum-bound cyclopentadienyl coordinates axially with respect to this Molr₂ face. Information from this crystal structure, ³¹P NMR data (both solution and solid-state), and results with analogous tungsten—triiridium and tetrairidium clusters have been employed to suggest coordination geometries for the isomeric derivatives.     

Fe3(CO)8(C6H5NC)(μ3-S)2的合成和晶体结构

The title compound Fe_3(CO)_8(C_6H_5NC)(μ_3-S)_2 (Ⅰ) was synthesized by the reaction of C_6H_5NCS with Fe_3(CO)_12 at room temperature. The crystal and molecular structure of the title compound were determined by single ctystal diffraction method. Crystal data: monoclinic, space group P2_1/C, a=12.718(4)Å, b=26.164(10) Å, c=l3.741(7) Å, β=117.18(2) °, V=4067(2) Å3, Z=8, Dc=1.825 g/cm3. The structure was solved by direct method and difference Fourier synthesis, and refined by full-matrix Least-squares with anisotropic thermal paramaters, using 1990 observed reflections [Ⅰ＞3σ(Ⅰ)].The final residual factor was R＝0.076, Rw＝0.082. The substituted ligand (C_6H_5NC)in Fe_3(CO)_8(C_6H_5NC)(μ_3-S)_2 is connected to the Fe(3) atom of the distorted tetragonal pyramid Fe_3S_2 framework.     

Halide abstraction as a route to cationic molybdenum(IV) compounds: Crystal and molecular structure of [CpMoCI(MeCN)4][SbCl6]2 · MeCN

Treatment of CpMoC1₃(MeCN)₂ with SbCl₅ in acetonitrile solution provides the solvated cationic series [CpMoCl₂(MeCN)₃]⁺, [CpMoCl(MeCN)₄]²⁺ and [CpMo(MeCN)₆]³⁺ as hexachloroantimon(V)ate salts following sequential halide abstraction. Characterization follows from microanalytical and spectroscopic (IR, and ¹H NMR) data and, in the case of [CpMoCl(MeCN)₄][SbCl₆]₂ · MeCN, by X-ray crystallographic studies. The structure is disordered but individual cations contain a six coordinated pseudo-octahedral metal geometry in which the cyclopentadienyl ligand (regarded as unidentate) and the chlorine atom occupy axial positions with an equatorial array of four acetonitrile ligands.     

The crystal structure, thermal behaviour and ionic conductivity of a novel lithium gadolinium polyphosphate LiGd(PO3)4

Crystal structure and ionic conductivity of lithium gadolinium polyphosphate, LiGd(PO₃)₄, were investigated. Single crystals of the title compound have been grown by a flux technique. The structure of this novel phosphate was determined by single crystal X-ray diffraction techniques. LiGd(PO₃)₄ is isotypic with LiNd(PO₃)₄. It crystallizes in the monoclinic space group C2/c with the unit cell parameters a=16.386(2), b=7.059(3), c=9.677(2) Å, β=126.12(1)°, V=904.2(4) Å³ and Z=4. The structure refined from 967 independent reflections leads to R₁=0.0167 and wR₂=0.0458. The lattice of LiGd(PO₃)₄ is built of twisted zig-zag chains running along with the b direction and make up of PO₄ tetrahedra sharing two corners, connected to the GdO₈ and LiO₄ polyhedra by common oxygen atoms to form a three-dimensional framework. Differential and thermogravimetric thermal analysis are given. The thermal curve of this compound was recorded and interpreted in agreement with impedance measurements. The ionic conductivity has been measured on pellet of the polycrystalline powder and evaluated as a function of temperature. This phase showed the conductivity of 2×10⁻⁶ and 2×10⁻⁴ Ω⁻¹ cm⁻¹ at 682 and 951 K, respectively.     

[Na4(H2O)7][Fe(OH)6Mo6O18]: A new [12] metallacrown-6 structure with an octahedrally coordinated iron at the center

The reaction of an aqueous solution of sodium molybdate with iron powder at low pH (∼0.184) gives rise to the formation of a six-member Mo ring-shape cluster with an Fe (II) encapsulated at the center, [Na₄(H₂O)₇][Fe(OH)₆Mo₆O₁₈](1), which is further linked to a remarkable three-dimensional network via sodium ions.     

Synthesis, structure determination, and infrared spectroscopy of (NpO2)2(SO4)(H2O)4: Prevalence of cation-cation interactions and cationic nets in neptunyl sulfate compounds

The compound (NpO₂)₂(SO₄)(H₂O)₄ was synthesized by evaporation of a Np⁵⁺ sulfate solution. The crystal structure was determined using single crystal X-ray diffraction and refined to an R₁=0.0310. (NpO₂)₂(SO₄)(H₂O)₄ crystallizes in triclinic space group P-1, a=8.1102(7) Å, b=8.7506(7) Å, c=16.234(1) Å, α=90.242(2)°, β=92.855(2)°, γ=113.067(2)°, V=1058.3(2) Å³, and Z=2. The structure contains neptunyl pentagonal bipyramids that share vertices through cation-cation interactions to form a sheet or cationic net. The sheet is decorated on each side by vertex sharing with sulfate tetrahedra, and adjacent sheets are linked together through hydrogen bonding. A graphical representation of (NpO₂)₂(SO₄)(H₂O)₄ was constructed to facilitate the structural comparison to similar Np⁵⁺ compounds. The prevalence of the cationic nets in neptunyl sulfate compounds related to the overall stability of the structure is also discussed.