Synthesis and crystal structure of Ba2[(UO2)(C2O4)2(NCS)]NCS·7H2O

Single crystals of Ba₂[(UO₂)(C₂O₄)₂(NCS)]NCS · 7H₂O were prepared and studied by X-ray diffraction. The crystals are monoclinic, space group P2₁/c, Z = 4, a = 13.508(5) Å, b = 12.268(4) Å, c = 14.965(5) Å, β = 115.38(1)°, V = 2240.6(13) ų. The main structural units in the crystal are the island complex species [(UO₂)(C₂O₄)₂(NCS)]^3? corresponding to the crystal chemical group AB ₂ ⁰¹ M¹ (A = UO ₂ ²⁺ , B⁰¹ = C₂O ₄ ^2? , M¹ = NCS^?) of uranyl complexes, which are united into a three-dimensional framework through electrostatic interactions and through hydrogen bonds involving oxalate and isocyanate ions and water molecules.     

Synthesis and Crystal Structure of (C6N3H18)2Ti4O4(C2O4)7·4H2O

The title compound (C6N3H18)2Ti4O4(C2O4)7(4H2O 1 (C13H22N3O18Ti2, Mr = 604.14) was synthesized by the reaction of Ti(SO4)2, H2C2O4(2H2O and N-(2-ammonioethyl)- piperazinium (AEPP) in aqueous solution. The single-crystal X-ray analysis has revealed that 1 crystallizes in the triclinic system, space group Pī with a = 9.1437(6), b = 11.4991(10), c = 11.6975(8)A, α = 96.2915(18), β = 107.998(3), γ = 104.276(4)°, V = 1110.35(14)A3, Z = 2, Dc = 1.807 g/cm3, F(000) = 618, μ = 0.815 mm－1, the final R = 0.0463 and wR = 0.1264 for 3718 observed reflections with I > 2σ(I). X-ray crystal-structure analysis suggests that compound 1 consists of [Ti4O4(C2O4)7]6－ anion and two protonated N-(2-ammonioethyl)piperazinium cations. The anions are linked into an infinite chain through Ti4O4(C2O4)8 by sharing the oxalates as bridging ligands.     

Synthesis,crystal structure,and catalytic performance of two 3-D supramolecular compounds: (C7N2H7)3(C7N2H6) · PMo12O40 · 2H2O and (C7N2H7)3(C7N2H6)2 · AsMo12O40 · 3H2O

Two organic–inorganic compounds based on Keggin building blocks have been synthesized by hydrothermal methods, (C₇N₂H₇)₃(C₇N₂H₆)?·?PMo₁₂O_40?·?2H₂O (1) and (C₇N₂H₇)₃(C₇N₂H₆)_2?·?AsMo₁₂O_40?·?3H₂O (2) (C₇N₂H₆?=?benzimidazole). Single-crystal X-ray analysis revealed that 1 crystallized in the triclinic system, P-1 space group with a?=?9.8980(4)?Å, b?=?11.2893(4)?Å, c?=?25.8933(9)?Å, α?=?93.307(2)°, β?=?90.630(2)°, γ?=?108.330(2)°, V?=?2740.68(18)?ų, Z?=?2, R ₁(F)?=?0.0740, ωR ₂(F ²)?=?0.1511, and S?=?1.037; 2 crystallized in the triclinic system, P-1 space group with a?=?12.3353(4)?Å, b?=?13.2649(4)?Å, c?=?20.2878(6)?Å, α?=?95.6630(10)°, β?=?100.1720(10)°, γ?=?99.3940(10)°, V?=?3195.72(17)?ų, Z?=?2, R ₁(F)?= 0.0329, ωR₂ (F ²)?=?0.1236, and S?=?1.088. The two compounds show a layer framework constructed from Keggin-polyoxoanion clusters and benzimidazole via hydrogen bonds and π–π stacking interactions, resulting in a 3-D supramolecular network. Both have high catalytic activity for oxidation of methanol. When the initial concentration of the methanol is 5.37?g?m^?3 in air and the flow velocity is 4.51?mL?min^?1, methanol is completely eliminated at 150°C for 1 (160°C for 2).     

Synthesis, crystal structure, and thermal stability of [Mo2O4(μ2-O)(C6H4O2)2(H2O)] · (C8H9N2)2 · 2H2O

From hydrothermal treatment of benzene-1,2-diamine, pyrocatechol, and MoO₃ in acetic acid solution, a new compound, [Mo₂(μ₂-O)₂(C₆H₄O₂)₂(H₂O)] · (C₈H₉N₂)₂ · 2H₂O (I), constructed from pyrocatechol chelated dinuclear molybdenum units and 2-methylbenzimidazole has been synthesized. Single-crystal structure analysis reveals that the compound crystallizes in the monoclinic space group P2₁/c with a = 23.365(2), b = 7.2214(5), c = 19.3021(16) β = 97.929(4), V = 3225.6(5), Z = 4, M = 808.46, ρ_c = 1.665 g/cm³, μ(MoK _α) = 0.84 mm^?1, F(000) = 1608, the final R = 0.0622 and wR = 0.1484 for 7385 independent reflections with R _int = 0.0393. Interestingly, an in situ condensation between acetic acid and benzene-1,2-diamine has occurred, and the unexpected 2-methyl-1-H-benzo[d] imidazoles serve as counterions and N-H donors to form stable hydrogen-bond network in the crystal. Furthermore, intermolecular hydrogen bonds are found among the cations, anions and crystalline water molecules. The double nuclear molybdenum units are connected by O-H...O hydrogen bonds with the crystalline water molecules to form one-dimensional chains, and the chains are further joined together by N-H...O to form a quasi-two dimensional structure.     

Synthesis and crystal structure of a novel tartrate copper(II) two-dimensional coordination polymer: {[Cu2(C4H4O6)2(H2O)2]·4H2O}∞

A new 2D coordination polymer, {[Cu₂(C₄H₄O₆)₂(H₂O)₂]·4H₂O}_∞ has been synthesized by the hydrothermal method and characterized by X-ray single crystal diffraction. Every copper(II) atom adopts a distorted octahedral geometry and coordinates with six oxygen atoms from one water molecule and three tartrate acid ions. The two tartrate acid ions have different coordination modes, one provides four oxygen atoms to coordinate with Cu(II) and another coordinates with all six oxygen atoms. Such a coordination mode generates a two-dimensional coordination polymer. In the solid state, the title compound forms a 3D network structure through hydrogen bonds.     

(NH4)(CN3H6)2[UO2(C2O4)2(NCS)] · 2H2O: Synthesis and crystal structure

A single-crystal X-ray diffraction study (NH₄)(CN₃H₆)₂[(UO₂(C₂O₄)₂(NCS)] · 2H₂O (I) was carried out. The crystals are orthorhombic, space group P2₁2₁2₁, Z = 4, with the unit cell parameters a = 6.668(2) Å, b = 13.463(4) Å, c = 23.086(6) Å. The main structural units of the crystals of I are insular complex anions [(UO₂)(C₂O₄)₂(NCS)]^3?. They belong to the crystal-chemical group AB ₂ ⁰¹ M¹ (A = UO ₂ ²⁺ ) of uranyl complexes and are linked into a three-dimensional framework through electrostatic interactions and hydrogen bonds with the participation of ammonium and guanidinium cations and crystal water molecules.     

Synthesis and crystal structure of the lithium perrhenate monohydrate LiReO4·H2O

A new monohydrate of lithium perrhenate LiReO₄·H₂O was prepared by dehydration of LiReO₄·1.5H₂O at room temperature. The single crystals of LiReO₄·H₂O were obtained by crystallisation from the isoamyl acetate solution of LiReO₄·1.5H₂O. The structure of monohydrate (a=5.6674(4), b=10.771(1), c=7.4738(7) Å, β=102.422(7)°, R₁=0.0414, space group P2₁/a, Z=4) is built up from LiO₃(H₂O)₂ trigonal bipyramids and ReO₄ tetrahedra sharing common edges and corners inside the layers. The layers are connected together by hydrogen bonds. The relationships between the structures of sesquihydrate, monohydrate and anhydrous LiReO₄ are discussed.     

Synthesis and crystal structure of a neutral open framework cobalt(II) phosphate Co6(PO4)4·7H2O with a channel structure

Using tri-ethyl phosphate as a phosphate source, the hydrothermal reaction of cobalt(II) oxalate di-hydrate, zinc oxide and 1,8 di-amino octane at 200°C gave purple crystals of Co₆(PO₄)₄?·?7H₂O (1), along with a mixture of open-framework zinc–cobalt phosphates Co–Zn–HPO₄, and Co₃(HPO₄)₂(2OH). Compound 1, has been characterized by thermal analysis, FTIR and single crystal X-ray diffraction. The single crystal structure of Co₆(PO₄)₄?·?7H₂O reveals cobalt in four, five and six-fold coordination with linkages through the bridging water molecules and the oxygen atoms of the phosphate in the subunits. Four subunits are connected together through the oxygen atoms (PO₄), to form the three dimensional open framework structure, with a 20-member ring channel that hosts two uncoordinated water molecules. Thermal removal of the water molecules occurs between 400–600°C, with the collapse of the structure above 600°C.     

Synthesis and crystal structure of the hydrated magnesium diphosphate Mg2P2O7·3.5H2O and its high temperature variant Mg2P2O7·H2O

The synthesis and crystal structure of a novel hydrated magnesium diphosphate and its high temperature variant are described. Both structures were solved from powder X-ray diffraction data. The room temperature variant with composition Mg₂P₂O₇·3.5H₂O crystallises in the monoclinic space group P2₁/c (No. 14) with a=10.9317(1), b=8.05578(9), c=9.2774(1) Å, β=90.201(1)°, V=816.99(2) ų and Z=4. The structure consists of sheets stacked along [100] which are linked through MgO₂(H₂O)₄ pillars into a three-dimensional framework with cavities containing water molecules. Within the sheets there are infinite edge-sharing chains of Mg octahedra along [010] which are cross linked by P₂O₇⁴⁻ groups. A high temperature variant exists around 200°C. The crystal structure of this compound with composition Mg₂P₂O₇·H₂O was solved and refined in the monoclinic space group C2/c (No. 15) with a=18.6596(4), b=7.9769(1), c=8.9757(2) Å, β=107.378(1)°, V=1275.01(4) ų, Z=8. The transformation to Mg₂P₂O₇·H₂O involves removal of the water molecules in the cavities and the water molecules of the Mg octahedral pillars in Mg₂P₂O₇·3.5H₂O. The sheets in Mg₂P₂O₇·3.5H₂O however remain unchanged during the transformation as the water molecule coordinating Mg here is retained. These sheets are linked through tetrahedral MgO₄ pillars into a three-dimensional structure containing infinite 10-membered ring channels along [001]. Both compounds have been further characterised by ³¹P MAS NMR spectroscopy, thermogravimetric analysis and high temperature powder X-ray diffraction.     

Synthesis and crystal structure of Cs2[(UO2)2(C2O4)3] and Cs2[UO2(C3H2O4)2] · H2O

Cs₂[(UO₂)₂(C₂O₄)₃] (I) and Cs₂[UO₂(C₃H₂O₄)₂] · H₂O (II) have been synthesized and studied by X-ray diffraction. The crystals of complexes I and II are monoclinic: a = 8.1453(2) Å, b = 8.9831(2) Å, c = 11.3897(4) Å, β = 104.0950(10)°, V = 808.29(4) ų, space group P2₁/n, Z = 2, and R ₁ = 0.0255 for I and a = 9.6998(2) Å, b = 17.8686(3) Å, c = 8.2074(2) Å, β = 97.5780(10)°, V = 1410.10(5) ų, space group P2₁/c, Z = 4, and R ₁ = 0.0287 for II. The uranium-containing structural units of complexes I and II are [(UO₂)₂(C₂O₄)₃]^2? chains and [UO₂(C₃H₂O₄)₂] ₂ ^4? dimers, which belong to the AK _0.5 ⁰² T¹¹ and AT¹¹B⁰¹ crystallochemical groups (A = UO ₂ ²⁺ , K⁰² and T¹¹ = C₂O ₄ ^2? , T¹¹ and B⁰¹ = C₃H₂O ₄ ^2? ) of uranyl complexes.     

Synthesis,crystal structure of Gd(H2O)(C2O4)2 · NH4 and of La(C2O4)2 · NH4. Characterization of the Ln(H2O)(C2O4)2 · NH4 with Ln=Eu…Yb

Single crystals of two lanthanide complexes, presenting similar formula Ln(H₂O)_x(C₂O₄)₂ · NH₄ with Ln=La, x=0 and Ln=Gd, x=1, have been prepared, in closed system at 200 °C. The gadolinium complex is bi-dimensional. A layer is built by the packing of the basic unit, [Gd(C₂O₄)]₄. The gadolinium atoms are related only by bischelating oxalate ligands, the ammonium ion and the water molecule (bound to the gadolinium atom) are localized into the interlayer space. The lanthanum complex is tri-dimensional. The basic building unit remains approximately the same and the packing of these units form a layer. However, within these units, the lanthanum atoms are related by either an oxalate ligand or an edge. Moreover, an oxalate ligand assumes the connection between the layers. The ammonium ion is localized into two sets of intersecting channels. Pure phase of the gadolinium complex has been prepared at 100 °C and extended to some lanthanide elements, Eu…Yb. As the size of the lanthanide ionic radius is decreasing, it is noticeable that the a unit–cell constant follows an expansion pattern while the others two follow an usual contraction one. The thermal behavior of this family shows that the anhydrous compounds are obtained and that some water molecule is sorbed during the cooling. Thus, the anhydrous compounds present a relatively open-framework with some small micropores.     

Synthesis and structure assignment of vanadyl(iv) citrate [(VO)3(C6H5O7)2]·H2O

Pseudo-crystals of vanadyl(iv) citrate [(VO)₃(C₆H₅O₇)₂]·H₂O have been obtained after addition of V₂O₅ to citric acid solution. Composition of the compound has been established by thermal analysis and confirmed by IR, UV-VIS, Raman and ESR spectra.     

Synthesis, crystal structure and electrochemical property of 2D lamellar supermolecular complex [Cu(C6H4NO2)2 · H2O]

A 2D lamellar supermolecular complex [Cu(C₆H₄NO₂)₂ · H₂O] was synthesized and characterized by elementary analysis, infrared spectrum, ultraviolet spectrum, thermogravimetry analysis and crystal X-ray diffraction analysis. The complex belongs to the orthorhombic system, Pbca space group, with a = 1.2797(8), b = 1.2944(8), c = 1.4962(9) nm, Z = 8, V = 2.478(3) nm³, D _c = 1.746 g cm^?3, ?? = 1.784 mm^?1, F(000) = 1320, R ₁ = 0.0267, wR ₂ = 0.0762, GOOF = 1.015, which consists of a Cu(II) ion, two 2-Picolinic acid and a coordinated water molecule. The 5-coordinated geometry of the Cu cation is a distorted tetragonal-pyramidal configuration. The 1D chain structure is formed through hydrogen bonds O(w)-H??O between single cells, and the 2D lamellar supermolecular system is formed through the non-classical hydrogen bonds C-H??O between various chains. The complex displays a distinct absorption band (??_max = 648 nm) in aqueous solution. The electrochemical behavior shows a quasi-reversible course. (CCDC: 750880)     

Synthesis and Crystal Structure of [Ni(H2O)6][Ni(H2O)2(C4H2O4)]·4H2O

Reaction of a freshly prepared Ni(OH)_{2?2 x} (CO₃) _x ·yH₂O with maleic acid in H₂O at room temperature afforded [Ni(H₂O)₆][Ni(H₂O)₂(C₄H₂O₄)]·4H₂O, which consists of [Ni(H₂O)₆]²⁺ cations, [Ni(H₂O)₂(C₄H₂O₄)]^2? anions and lattice H₂O molecules. Ni atoms in cations are octahedrally coordinated and Ni atoms in anions are each octahedrally coordinated by bidentate chelating maleato ligands and two water molecules at trans positions. Cations and anions are interlinked by hydrogen bonds to form 1D chains, which are hexagonally arranged and connected by the lattice water molecules. When heated in a flowing argon stream, the compound decomposes, with complete dehydration being followed by dissociation of nickel maleate into NiO and maleic anhydride.     

Synthesis and crystal structure of [UO2CrO4(C5NH5COO)] · 0.25H2O

[UO₂CrO₄(C₅NH₅COO)] · 0.25H₂O crystals have been synthesized and studied by X-ray diffraction and IR spectroscopy. The compound crystallizes in monoclinic system with the unit cell parameters a = 7.2362(3) ?, b = 13.8847(6) ?, c = 10.7204(5) ?, ?? = 90.037(2)°, space group P2₁/n, Z = 4, R = 0.0236. The structure consists of [UO₂CrO₄(C₅NH₅COO)] chains, which run in the direction [100] and correspond to the AT³B⁰¹ crystallochemical formula, where A = UO ₂ ²⁺ , T³ = CrO ₄ ^2? , and B⁰¹ is nicotinic acid molecules in the form of zwitter ions. The results of analyzing nonbonded interactions in the crystal structure by the method of molecular Voronoi-Dirichlet polyhedra (MMVDP) are presented.     

Synthesis and Crystal Structure of [Cu(phen)2(SO4)(H2O)]·0.5C4H4O4·7H2O

The title compound, [Cu(phen)2(SO4)(H2O)]·0.5C4H4O4·7H2O (phen = 1,10-phe-nanthroline and C4H4O4 = fumaric acid), has been synthesized and characterized by single-crystal X-ray diffraction. The crystal is of triclinic, space group P with a = 11.4827(2), b = 11.9086(2), c = 13.77350(10)(A), α = 80.6830(10), β = 66.6480(10), γ = 64.0480(10)o, V = 1554.63(4) (A)3, Mr = 722.17, Z = 2, Dc = 1.543 g/cm3, μ = 0.845 mm-1, F(000) = 750, R = 0.0349 and wR = 0.0837 for 4754 observed reflections (I > 2σ(I)). The compound contains a six-coordinated copper(II) center, which is surround by four N atoms of two phen ligands (Cu-N distances in the range of 1.997(2)～2.225(2)(A)), one sulfate O atom (Cu-O = 2.0037(17) (A)) and one water O atom (Cu-O(5w) = 2.719(2) (A)) in a distorted octahedral geometry. Extensive hydrogen-bonding interactions are involved in water molecules, ligated sulfate anions and fumaric acid molecules. In addition, π-π interactions via aromatic nitrogen-containing ligands are also discussed. The combination of non-covalent interactions leads to the formation of a 3-D network structure.     

Synthesis and structure of [UO2(SeO4)(C2H4N4)2] · 0.5H2O

The single-crystal X-ray diffraction analysis of [UO₂(SeO₄)(C₂H₄N₄)₂] · 0.5H₂O (I) is performed. The crystals are monoclinic: space group C2/c, Z = 8, a = 19.035(2), b = 7.1326(8), c = 21.477(2) Å, β = 109.683(4)°. The main structural units of the crystal are chains of [UO₂(SeO₄)(C₂H₄N₄)₂]. Compound I belongs to the crystal-chemical group AT³M ₂ ¹ (A = UO ₂ ²⁺ , T³ = SeO ₄ ^2? , M¹ is a cyanoguanidine molecule) of the uranyl complexes. The chains are united into three-dimensional framework through hydrogen bonds involving the oxygen atoms of the selenate and uranyl groups, the nitrogen atoms of cyanoguanidine, and the hydrogen atoms of the cyanoguanidine or water molecules.