Crystal structure and electrochemical behavior of a novel polyoxometalate [Ni(bpy)3]2[W4V2O19] with Lindqvist‐type structure

A novel polyoxometalate [Ni(bpy)₃]₂[W₄V₂O₁₉] (Ni₂V₂W₄) has been synthesized by the hydrothermal method and the structure determined by X‐ray crystallography. Ni₂V₂W₄ crystallizes in a trigonal system with space group R ‐3c (a = 15.8984 (5) Å, b = 15.8984 (5) Å, c = 43.855 (3) Å). In the structure of the compound, terminal and bridging oxygen atoms are bond to the metal centers by σ or π bonds. The W⁶⁺ and V⁵⁺ ions in isopolyanion [W₄V₂O₁₉]^4‐ statistically distribute over the six metal centers. Using cathodic adsorptive voltammetric method with a carbon paste electrode, the redox property and the electron transferring process were studied. The results show that electrochemical behavior about W(VI) and V(V) atoms give one‐electron, three‐electron and two‐electron reduction waves. Three successive oxidation waves are observed too. The compound was also characterized by thermal gravimetric analysis and IR spectra. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal Structure of pyridinium isopolymolybdate (C5H6N)2n[Mo4O13]n

Synthesis and crystal structure are described for pyridinium isopolymolybdate of chemical composition (C₅H₆N)_2n[Mo₄O₁₃]_n. The crystals are triclinic, space group P1, with the following unit‐cell parameters: a =8.2695(11) Å, b =10.544(4) Å, c =11.177(4) Å, α = 71.76(5)°, β = 89.68(3)°, γ = 78.79(3)°, V =906.4(4) ų, Z = 2 (chemical formula (C₅H₆N)₂[Mo₄O₁₃]), D _calcd = 2.755 g·cm^–3. Crystal structure was solved by Patterson methods and refined to a final R value 0.085 for 4045 independent reflections. The studied compound, considered in analogy to triclinic (NH₄)₂Mo₄O₁₃ as pyridinium polyoctamolybdate, is proposed to be better described as pyridinium isopolytetramolybdate (C₅H₆N)_2n[Mo₄O₁₃]_n. It seems that the proper coordination number of molybdenum (VI) ions is five, resulting in pyramidal coordination polyhedra [MoO₅]. Coordination polyhedra joined by common edges form tetramolybdate monomeric unit [Mo₄O₁₃]. The mers are connected by oxygen bridges Mo ‐ O ‐ Mo into infinite ribbon chains. Each two infinite chains are hold together by weaker intermolecular interactions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal structure and phase transition in the compound [C6H5CH2NH(CH3)2]TlCl4

The N‐N dimethyl benzylammonium tetrachlorothallate (III) [C₆H₅CH₂NH(CH₃)₂]TlCl₄ crystallizes in the monoclinic system P2₁/n at room temperature with the following unit cell dimensions: a = 7.725(3) Å, b = 14.080(5) Å, c = 13.697(4) Å, β = 91.2(2)° with Z = 4. The structure shows a layer arrangement perpendicular to the b axis: planes of [TlCl₄]^‐ tetrahedra alternate with planes of [C₆H₅CH₂NH(CH₃)₂]⁺ cations. The cohesion of the atomic arrangement is ensured by hydrogen bonds N‐H…Cl. Differential scanning calorimetric and optical birefringence measurements reveals a phase transition at T = 339K. Raman spectroscopic study and dielectric measurements were performed to discuss the mechanism of the phase transition. (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and crystal structure of a new inorganic – organic complex: (4‐ClC7H6NH3)9[Nd(P6O18)2]·9H2O

Single crystals of (4‐ClC₇H₆NH₃)₉[Nd(P₆O₁₈)₂]·9H₂O were synthesized in aqueous solution. This compound crystallizes in a triclinic P1 unit‐cell, with a = 14.898(6), b = 18.049(7), c = 20.695(6)Å, α = 102.04(3), β = 100.49(3), γ = 98.82(3)°, V = 5245(4) ų and Z = 2. The crystal structure has been solved and refined to R = 0.043 (Rw = 0.061) for 20420 observed reflections. The atomic arrangement of the title compound can be described as infinite layers built by complex of Neodyme [Nd(P₆O₁₈)₂] and nine water molecules. The organic cations are located in the space delimited by the successive inorganic layers. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The Crystal Structure of the Cluster Complex [{Co(phen)2}2V4O12] · H2O

The crystal structure of [{Co(phen)₂}₂V₄O₁₂] · H₂O consists of hexanuclear bimetallic clusters [{Co(phen)₂}₂V₄O₁₂]. The cyclic [V₄O₁₂]^4‐ anion acts as a bidentate bridging ligand between the two [Co(phen)₂]²⁺ cations. The π‐π stacking interactions between the parallel 1,10‐phenantroline (phen) groups play a significant role in stabilizing this structure. The title compound crystallizes in the P2₁/c space group.     

Structural and spectroscopic study of Mg13.4(OH)6(HVO4)2(H0.2VO4)6

Single‐crystals of the polar compound magnesium hydrogen vanadate(V), Mg_13.4(OH)₆(HVO₄)₂(H_0.2VO₄)₆, were synthesized hydrothermally. It represents the first hydrogen vanadate(V) among inorganic compounds. Its structure was determined by single‐crystal X‐ray diffraction [space group P 6₃mc, a = 12.9096(2), c = 5.0755(1) Å, V = 732.55(2) ų, Z = 1]. The crystal structure of Mg_13.4(OH)₆(HVO₄)₂(H_0.2VO₄)₆ consists of well separated, vacancy‐interrupted chains of face sharing Mg2O₆ octahedra, with short Mg2—Mg2 distances of 2.537(1) Å, embedded in a porous magnesium vanadate 3D framework having the topology of the zeolite cancrinite. All three hydrogen positions in the structure were confirmed by FTIR spectroscopy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A Novel Three Dimensional Organic–Inorganic Hybrid Based Porous Phase: Synthesis and Characterization of Reduced Oxovanadium pyromellitate, [VIV2O2(H2O)2(C6H2(COO)4)]

The hydrothermal reaction of a mixture of VOSO₄ · xH₂O, 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid) and 0.1 M H₂SO₄ for 72 h at 160 °C gives blue needle like crystals of [V^IV ₂O₂(H₂O)₂(C₆H₂(COO)₄)] in 30% yield. The compound has a porous 3-D extended network structure having a rigid architecture which is held together by the multidentate functionalities of 1,2,4,5-benzenetetracarboxylate ligand. Crystal data for the compound: monoclinic space group C 2/c (No:15), a = 11.756(5) ?, b = 9.645(3) ?, c = 11.822(7) ?, β = 107.10(4)°, Z = 8. The compound constitutes the first example of a fully reduced oxovanadium based solid incorporating the organic ligand. This article consists of synthesis, crystal structure and characterization of [V^IV ₂O₂(H₂O)₂(C₆H₂(COO)₄)].     

Structure of (N-(2-hydroxyphenyl)-salicylaldiminopiperidino) Ni(II) complex

The crystal and molecular structure of the title complex, C₁₈H₁₉N₂O₂Ni, has been determined by direct methods. The compound crystallizes in the monoclinic crystal system witha=22.973(1),b=5.212(1),c=27.076(1)Å, β=106.46(1)°, space groupC2/c,V=3109.1(6)ų, Z=8, andD _x=1.51g cm^?3. The nickel atom is in a slightly distorted square-planar environment of two oxygens [Ni(1)?O(1) 1.824(3) and Ni(1)?O(2) 1.856(3)Å] and two nitrogens [Ni(1)?N(1) 1.849(3) and Ni(1)?N(2) 1.932(3)Å] with O?Ni?N angles between 85.7(1) and 97.1(1)°. The nickel atom is 0.006 Å out of the plane of its ligands.     

Nonlinear optical properties of strontium tartrato‐antimonate(III) dihydrate,Sr[Sb2{(+)‐C4H2O6}2]·2H2O

The tensor of nonlinear optical susceptibility for second harmonic generation [d^SHG _ijk ] of hexagonal (point group 6) strontium tartrato‐antimonate(III) dihydrate, Sr[Sb₂{(+)‐C₄H₂O₆}₂]·2H₂O, was determined using the Maker fringes method and a Nd:YAG laser with a wavelength of 1064 nm. The largest component of the tensor d^SHG ₃₃₃ amounts two times d^SHG ₁₁₁ of α‐quartz. Effective nonlinear optical susceptibility d^SHG _eff is given for phase matching type I for several wavelengths (for type II d^SHG _eff is nearly zero). The thermal stability of crystals of Sr[Sb₂{(+)‐C₄H₂O₆}₂]·2H₂O was determined in the temperature range from 153 K to 573 K by means of thermal expansion measurements and thermogravimetry. The temperature dependence of thermal expansion coefficients is given in the range from 153 K to 293 K. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal Structure of 5,6‐Dinitrobenzimidazole.monohydrate

The title compound (C₇H₆N₄O₅) crystallizes in the monoclinic space group P2₁/c with a=8.566(1) Å, b=14.493(3) Å, c=7.583(1) Å, β=87.75(1)°, V=940.7(3) ų, Z=4, D_x=1.597 g.cm^‐3. The structure was solved by direct methods and refined by full‐matrix least‐squares method (R=0.0696). The title compound consists of an imidazole ring with the two NO₂ groups and one water molecule. The short inter‐ molecular N‐H^…N [2.03(5) Å] and O_water‐H^…O [1.98(5) Å] hydrogen bonds are highly effective in holding the molecule in a stable state as a whole.     

Influence of complex formation upon inclusion of Mn(II), Co(II), Ni(II), and Cu(II) in ZnC2O4·2H2O

The inclusion of 3d‐impurities Mn(II), Co(II), Ni(II) and Cu(II) in a crystalline precipitate of ZnC₂O₄·2H₂O is investigated. This study is a part of the systematic one deal with the mechanism of inclusion of 3d‐ions in sparingly soluble oxalate systems. The experiments are carried out in bi‐ end multi‐component systems at two different mediums – one with deficiency of oxalate ions, another with excess. The insertion of 3d‐ions upon mass crystallization of ZnC₂O₄·2H₂O does not proceed by a simple ionic substitution. The results show that the inserted amount of impurity depends on some physicochemical characteristics of the neutral monooxalato complexes [MnC₂O₄]^o, [CoC₂O₄]^o, [NiC₂O₄]^o and [CuC₂O₄]^o. Good agreement between included impurity and the concentration of its complex in the solution is established. The stability constant of monooxalato complex affects the impurity inclusion. This effect depends on the medium nature. In the deficiency of oxalate ions the factor determining the inclusion is thermodynamic one – stability of monooxalato complexes. In the excess of oxalate ions inserted amount depends on kinetic factor – the formation rate of these complexes. In the term of that the insertion of Mn(II) is definitely different in the two mediums while that of the Ni (II) does not depend on the medium. The copper shows deviation from overall dependence in the two mediums due to the Jahn‐Teller distortion. Its double decreasing insertion in the excess of oxalate ions is related with stabilization of [Cu(C₂O₄)2]^2‐. The conclusions presume that by varying the background medium and taking in view the ions present in the solution, the amount of inserted impurities can be predicted and controlled. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and structure of (NH4)4[(DMF)2Mo8O26]· 2CH3CH2OH·2H2O (DMF= N , N -dimethylformamide)

A new organic-inorganic hybrid γ-octamolybdate complex, (NH₄)₄[(C₃H₇NO)₂Mo₈O₂₆]·2CH₃CH₂OH·2H₂O was synthesized from the mixture of ethanol, DMF, 4-aminobenzoic acid, (NH₄)₆Mo₇O₂₄·4H₂O, HCl and H₂O. The structure was determined by X-ray crystallography. It crystallizes in monoclinic P2₁/n space group with the crystal cell parameters of a = 8.8825(4), b = 21.1608(10), c = 11.1343(6) ?, β = 104.7720(10)°, V = 2023.64(17) ?³ and Z = 2. The crystal X-ray analysis shows that two DMF molecules are bound to γ-octamolybdate anion. The molecular structure is stabilized by the complex hydrogen bonding.     

Crystal structure of N‐(3,4‐dichlorophenyl)‐N′‐hydroxy‐2‐oxo‐2‐phenylacetamidine

The title compound (C₁₄H₁₀N₂O₂Cl₂) crystallizes in the monoclinic space group P2₁/a with a=10.042(1) Å, b=10.317(1) Å, c=13.877(2) Å, β=97.36(2)°, V=1425.8(3) ų, Z=4, D_x=1.44 g.cm^‐3. The structure was solved by direct methods and refined by full‐matrix least‐squares method (R = 0.0457). The title molecule consists of 3,4‐dichlorophenylamino and 2‐phenyl‐1,2‐ethanedione‐1‐oxime groups. The intermolecular O‐H…N and N‐H…O hydrogen bonds [O…N 2.760(6) and 3.087(5) Å] are highly effective in forming the polymeric chains. The oxime group has an E configuration. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal structure of M4[(UO2)2C2O4(SO4)2(NCS)2] ( M = K+, Rh+) and K4[(UO2)2C2O4(SeO4)2(NCS)2]

Three heteroacidoligand uranyl complexes M ₄[(UO₂)₂C₂O₄(SO₄)₂(NCS)₂] (M = K⁺ (I), Rb⁺ (II)) and K₄[(UO₂)₂C₂O₄(SeO₄)₂(NCS)₂] (III) have been synthesized and their crystal structure has been determined by X-ray diffraction analysis. The compounds I–III are isostructural and crystallized in the monoclinic system, sp. gr. P2₁/c, Z = 2, a = 11.5548(3) ?, b = 7.0847(1) ?, c = 13.5172(3) ?, β = 93.130(1)°, V = 1104.90(4), R = 0.015 (I); a = 11.5854(9) ?, b = 7.3841(6) ?, c = 13.9072(9) ?, β = 95.754(3)°, V = 1183.74(15), R = 0.0235 (II); a = 11.6715(3) ?, b = 7.1418(2) ?, c = 13.8546(1) ?, β = 93.539(1)°, V = 1152.66(5), R = 0.0126 (III). Basic structural units of these crystals are [(UO₂)₂C₂O₄(XO₄)₂(NCS)₂]⁴⁻ chains, which belong to the crystallochemical group A ₂ K ⁰² B ₂² M ₂¹ (A = UO₂²⁺, K ⁰² = C₂O₂₋⁴, B ² = SO₄²⁻ or SeO₄²⁻, M ¹ = NCS⁻) of uranyl complexes. Uranium-containing chains are connected into a 3D framework via a system of electrostatic interactions with potassium or rubidium cations from outer spheres. Original Russian Text ? I.V. Medrish, E.V. Peresypkina, A.V. Virovets, L.B. Serezhkina, 2008, published in Kristallografiya, 2008, Vol. 53, No. 3, pp. 495–498.     

Synthesis and crystal structure of hexakis(N-methylimidazole) iron(II) pyridine-2-sulfonate

The compound [Fe(C₄H₆N₂)₆][C₅H₄NSO₃]₂ crystallized in the monoclinic space group, P2₁/n with unit cell parameters: a = 13.676(3), b = 8.345(2), c = 18.663(4) Å, = 106.40(3)° and Z = 2. The title compound consists of a [Fe(C₄H₆N₂)₆]⁺² hexacoordinated iron(II) cation and two C₅H₄NSO^– ₃ anions. In the cation the iron atom is coordinated to six N-methylimidazole imine nitrogen atoms in a distorted octahedral arrangement. The N1,N5,N1ⁱ,N5ⁱ atoms are coplanar and the iron lies in this plane.     

Crystal structure and IR spectroscopic study of (CN3H6)2[(UO2)2(C2O4)(CH3COO)4]

Compound (CN₃H₆)₂[(UO₂)₂(C₂O₄)(CH₃COO)₄] is synthesized and characterized by IR spectroscopy and single-crystal X-ray diffraction [a = 8.5264(2) Å, b = 13.8438(4) Å, c = 10.7284(2) Å, β = 103.543(1)°, space group P2₁/n, Z = 2, and R = 0.0258]. The main structural units of the crystals are binuclear [(UO₂)₂C₂O₄(CH₃COO)₄]^2? groups, which belong to the A ₂ K ⁰² B ₄ ⁰¹ crystal chemical group of uranyl complexes (A = UO ₂ ²⁺ , K ⁰² = C₂O ₄ ^2? , and B ⁰¹ = CH₃COO^?). The coordination polyhedron of the uranium atom is the UO₈ hexagonal bipyramid with the oxygen atoms of the uranyl ion at the axial positions. Uranium-containing groups and guanidinium cations are connected by electrostatic interactions and by the hydrogen bond system, which involves hydrogen atoms of guanidinium cations and oxygen atoms of oxalate and acetate anions. The results of the spectroscopic study of the compound agree with the X-ray diffraction data.     

Crystal structure of [Rb0.24(H2O)0.76]VO(H2O)(PO4), a new monoclinic variety in the series of layered vanadyl phosphates

The crystal structure of a new monoclinic variety of hydrous rubidium vanadyl phosphate [Rb_0.24(H₂O)_0.76]VO(H₂O)(PO₄) doped with Al³⁺ ions is studied by X-ray (R = 0.054) diffraction: a = 6.2655(4) Å, b = 6.2712(3) Å, c = 6.8569(5) Å, β = 107.805(7)°, space group P2₁/m, Z = 2, and D _x = 2.792 g/cm³. The new phase obtained by the hydrothermal synthesis in the V₂O₅-Rb₂CO₃-AlPO₄-H₂O system has a layer-type structure in which Rb atoms and water molecules are located between layers of vertexsharing [VO₅(H₂O)] octahedra and [PO₄] tetrahedra. Rb intercalates based on VOPO₄ · 2H₂O are described by general formula [Rb _x (H₂O)_{1 ? x} ]V _1?x ^V V _x ^IV O(H₂O)(PO₄), where x ≤ 0.5, and the amount of reduced vanadium and interlayer water molecules is determined by the amount of introduced rubidium atoms.     

Synthesis and crystal structure of bis[2-[N-(2-chlorophenyl)formimidayl]-1-naphtholato]-(6Cl)copper(II)

The title compound, bis[2-[N-(2-chlorophenyl)formimidayl]-1-naphtholato]-(6Cl) copper(II), [Cu(C₁₇H₁₁NOCl)₂] (1) was synthesized and its crystal structure was determined. The Compound 1 is monoclinic, space group P2 ₁/c with a = 9.146(3) Å, b = 18.724(3) Å, c = 16.230(2) Å, β = 96.46(1)°, V = 2761.8(11) ų, Z = 4, D _c = 1.503 g cm^?3, μ(Mo Kα) = 1.020 mm^?1, R = 0.0606 for 2361 reflections [I > 2σ(I)]. In the title compound, the Cu atom is coordinated by an N₂O₂ donor set from the imine-phenol ligand in a slightly distorted square planar coordination geometry, with the two phenolate O atoms being deprotonated. The Cu–O bond lengths are 1.878(4) and 1.889(4) Å, the Cu–N bond lengths are 1.980(5) and 1.985(5) Å. The angles O1–Cu–N1 and O2–Cu–N2 are 90.96(19) and 90.72(19)°, respectively.     

Crystal structure of an unusual four-coordinated copper(II) complex containing 1,10-o-phenanthroline and salicyclic acid crystal structure containing Cu(II) o-phen and salicyclic acid

We have synthesized a multi-ligand chelate copper(II) complex [Cu · (C₇H₅O₃] · (C₁₂H₈N₂) · H₂O₁ · (C₇H₆O₃)· NO₃, and determined its structure by X-ray diffraction method. The space group of the title compound is P2₁/a. It is monoclinic, with a = 14.227(4), b = 9.627(4), c = 19.008(7) Å, β = 102.06(3)·, Z = 4. The two salicyclic acid molecules in the cell are in different environments, one inner, the other outer. The geometry around Cu(II) is a four-coordinated distorted plane square. The two coordinating atoms are two nitrogen atoms from phenanthroline, one oxygen atom from salicyclic acid, one oxygen atom from water.     

Synthesis, structure and characterization of a new inorganic-organic hybrid complex (C3H5N2)2[Cd(C3H4N2)2Nb2O3F8]·2H2O

(C₃H₅N₂)₂[Cd(C₃H₄N₂)₂Nb₂O₃F₈]·2H₂O (C₃H₄N₂=imidazole) (1) was prepared from the hydrothermal reaction of Nb₂O₅, 3CdSO₄·8H₂O, C₃H₄N₂, HF and H₂O at 403 K, and characterized by single crystal X-ray diffraction and IR spectra. 1 crystallizes in the orthorhombic system, space group Pba2, with a=11.0192(9), b=16.8012(14), c=6.8717(6) ?, and Z=2. The crystal is made up of [Cd(C₃H₄N₂)₂Nb₂O₃F₈]²⁻ anions, [C₃H₅N₂]⁺ complex cations and H₂O molecules of crystallization. And the backbone of the compound is a one dimension coordination polymeric chain containing the anions. The complex cations and anions are linked through hydrogen bonding interactions. Co-crystallized water molecules fill in the pores and hydrogen bond to the host. Bond valence sums show that O1, O3 and F3 have much more negative charge, which are in agreement with the crystal structure that they act as bridging atoms.Supplementary material CCDC-606794 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge at http://www.ccdc.cam.ac.uk/ const/retrieving.html or from the Cambridge Data Centre (CCDC), 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44(0)1223-336033 or e-mail: deposit@ccdc.cam.ac.uk.