Crystal structure oftrans-dioxotetrapyridinerhenium(V) chloride dihydrate

The crystal structure of dioxotetrapyridinerhenium(V) chloride dihydrate has been determined by single crystal X-ray diffraction methods. The crystals are monoclinic with unit cell dimensionsa = 13·592(2),b = 11·973(2),c = 15·55(1) Å, = 116·2(1)°, and the space group isCc with 4 formula weights per unit cell. A total of 1279 independent reflexions were examined and the structure was refined by full-matrix least squares to anR value of 0·11. The structure was refined both with rigid pyridine groups and independent atoms. The molecular cation has a near linear arrangement of the O-Re-O group, with an average Re-O distance of 1·76(3) Å. The average Re-N distance is 2·15(4) Å. The molecular cations are packed in layers along the ¯101 direction with pyridine groups interleaved. The chloride ion and water molecules lie between these layers, and the structure is held together by electrostatic forces between the cations and the chloride ions, and by hydrogen bonds between the water molecules and chloride ions or oxygen atoms. The cation is substantially distorted from 4/mmm (D _4h) as a result of crystal packing.We thank the National Research Council of Canada for supporting this research.     

Adsorption ability of samples with nanoscale anatase to extract Nb(V) and Ta(V) ions from aqueous media

The adsorption ability of titanium dioxide samples with nanoscale anatase prepared by the sulfate method and Degussa (Evonik) P25, Hombfine N, and Hombikate UV-100 commercial agents with different compositions and characteristics to extract Nb(V) and Ta(V) ions from a model aqueous system has been investigated for the first time. It is established that the degree of sorption R (%) depends on the sorption conditions and the nature of analyte. It is demonstrated that the degree of sorption of Nb(V) ions in the presence of all samples is the highest (R _max = 99.9%) for Degussa P25, except for the peroxide-modified samples on which the maximum sorption of Ta(V) ions with R _max = 99.9% has been attained.     

Coordination of 4-Aminoantipyrine to Rhenium(V)

Abstract  

The reactions of trans-[ReOX₃(PPh₃)₂] (X = Cl, Br) with 4-aminoantipyrine (H₂pap) were studied, and the complexes cis-[ReX₂(pap)(H₂pap)(PPh₃)](ReO₄) (X = Cl (1), Br (2)) were isolated. The crystal structure of 2 was determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2₁ with a = 11.5145(6) ?, b = 11.5330(5) ?, c = 17.5492(9) ?, β = 105.322(2)°, V = 2247.6(2) ?³, Z = 2, C₄₀H₃₉N₆O₆PBr₂Re₂, M _r = 1262.97, D _c = 1.866 g cm⁻³, F(000) = 1208 and μ(Mo K _α) = 7.244 mm⁻¹, the final R = 0.0545 and wR = 0.1314. The ligand pap is coordinated through the doubly deprotonated amino nitrogen as an imide, and H₂pap acts as a neutral bidentate chelate, with coordination through the neutral amino nitrogen and the ketonic oxygen.     

I–V Characteristics of tris(2,4-pentanedionato)manganese(III) thin films

Amorphous thin films of tris(acetylacetonate)manganese(III) were deposited on Si(P) substrates by thermal sublimation in vacuum. The deposited films were probed with X-ray fluorescence. Their electrical properties were studied as insulators for Al/Mn(acac)₃/Si(P) metal–insulator–semiconductor devices. Those devices were characterized by the measurement of the gate-voltage dependence of their capacitance, from which the relative permittivity (RP) and density of the charges in the insulator were determined. It was found that values of the RP of tris(acetylacetonate)manganese(III) films grown on Si(P) wafers were in the range of 30–40, which can be find applications in gate related technological uses. The dc-electrical conduction in the complex film was studied at room temperature and in temperature range of (293–325 K). It was found that the data of the as-deposited films follow the trap-charge-limited space-charge-limited conductivity (TCL-SCLC) mechanism, while the data of the annealed sample in vacuum of about 10⁻³ Pa at about 100 °C for 10 min obey the Richardson–Schottky (RS) mechanism. The parameters of both mechanisms were determined. It was concluded that the density of charged defects in the insulating film is critically determined the mechanism of the current-transfer.     

Complexes of Ambidentate N,O-Donor Ligands with Rhenium(I) and -(V)

The reaction of the potentially bidentate ambidentate N,O-donor ligands 3-hydroxy-2-pyridinecarboxylic acid (Hhpc) and 3-hydroxy-2-(hydroxymethyl)pyridine (Hhhp) with trans-[ReOCl₃(PPh₃)₂] led to the isolation of the products [ReOCl(hpc)₂] (1) (from acetonitrile) and [ReOCl₂(hhp)(PPh₃)] (2) (from ethanol) respectively. In both complexes hpc and hhp are coordinated as bidentate N,O-donor chelates, rather than as O,O-donor ligands. From the reaction of [Re(CO)₅Cl] and Hhhp·HCl in ethanol the neutral complex fac-[Re(CO)₃Cl(Hhhp)] (3) was obtained, with N,O-coordination of Hhhp. Complex 1 crystallizes in the monoclinic space group P2₁/n with a?=?6.8782(3), b?=?20.0647(8), c?=?10.8692(4) Å, β?=?107.545(1)°, and Z?=?4. Complex 2 crystallizes in the triclinic space group P-1 with a?=?7.3523(4), b?=?8.1047(5), c?=?19.591(1) Å, α?=?91.133(2)°, β?=?93.656(2)°, γ?=?93.074(2)° and Z?=?2. Complex 3 has monoclinic P2₁/c symmetry with the cell parameters a?=?10.6452(5), b?=?11.1372(5), c?=?9.7229(5) Å, β?=?106.107(2)°, and Z?=?4.

Graphical Abstract

The reaction of the potentially bidentate ambidentate N,O-donor ligands 3-hydroxy-2-pyridinecarboxylic acid (Hhpc) and 3-hydroxy-2-(hydroxymethyl)pyridine (Hhhp) with trans-[ReOCl₃(PPh₃)₂] led to the isolation of the products [ReOCl(hpc)₂] (from acetonitrile) and [ReOCl₂(hhp)(PPh₃)] (from ethanol) respectively. In both complexes hpc and hhp are coordinated as bidentate N,O-donor chelates, rather than as O,O-donor ligands. From the reaction of [Re(CO)₅Cl] and Hhhp·HCl in ethanol the neutral complex fac-[Re(CO)₃Cl(Hhhp)] was obtained, with N,O-coordination of Hhhp. Spectroscopic data and the X-ray crystal structures of the complexes are reported.

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Structure of bis(2-pyridine-N-oxide) diselenide and its formation from tetraphenylantimony(V)selenopyridine-N-oxide

The structure of bis(2-pyridine-N-oxide) diselenide was determined by single crystal X-ray diffraction. The compound crystallized in the triclinic system and the structure was solved in the space group . The lattice constants were determined to bea=7.174(2),b=7.176(2),c=11.070(2) , =87.67(2)°, =73.68(2)°, and =89.57(2)°;Z=2,D _x=1.906 Mg m^–3. The final least squares refinement based on 1942 independent observed reflections yieldedR=0.033,wR=0.044. The Se–Se bond length is 2.326(1) and each Se is coordinated to the O atom of the corresponding N-oxide moiety at a distance of about 2.6 .     

Synthesis and structure of μ-oxo-bis [(acetylacetonato)(thioacetylacetonato)] dioxodimolybdenum(V) and υ-oxo-[tris(acetylacetonato)(thioacetylacetonato)]dioxodimolybdenum(V)

In the reaction of Mo₂O₃ (acac)₄ and Mo₂O₃ (OAc)₄ with thioacetylacetone two new complexes of molybdenum(V), Mo₂O₃ (acac)₂(Sacac)₂ (complexI) and Mo₂O₃(acac)₃(Sacac) (complexII), respectively, have been prepared. Their crystal structures have been determined from single crystal diffractometer data and refined to the finalR values of 0.068 and 0.044, respectively. Both complexes crystallize in the tetragonal space groupI4₁/a with cell dimensions, (I):a=21.646(3),c=11.627(2) Å,D _calc=1.630 g cm^–3,Z=8 and (II):a=21.240(3),c=11.688(2) Å,D _clac=1.644 g cm^3–,Z=8 and have essentially the same structure. In the structure of (II) half of thioacetylacetone of (I) is statistically replaced by acetylacetone causing thus an occupational disorder in this region of the structure. Both complex molecules are dinuclear and have crystallographically imposed ¯1 symmetry with the bridging oxygen atom in the center of symmetry. Molybdenum atoms exhibit distorted octahedral coordinations. Sulfur atom of the Sacac ligand in (I) shows a considerably largertrans influence than the oxo-oxygen atom.     

Structure oftrans-dichlorooxobis(triphenylphosphine)rhenium(V), ReCl2O(OEt)(Ph3P)2

C₃₈H₃₅Cl₂O₂P₂Re,M _r=842, triclinic,P¯1,a=17.71(2),b=11.33(1),c=9.82(1) Å,=114.60(3),=90.84(3), =78.05(3),V=1747(2) ų,D _m(flotation)=1.60,D _x=1.60 Mg m^–3 forZ=2, MoK, =0.7107 Å,=41.6 cm^–1,F(000)=836, room temperature. The structure was solved by standard methods from diffractometer data and refined to a conventionalR of 3.4% for 5412 observed reflections. The Re atom is six coordinate octahedral withtrans-Cl atoms andtrans-Ph₃P groups. Relevant bond distances are: Re-P 2.533(1) and 2.535(1) Å, Re-O(ethoxo) 1.888(4) Å, and Re-O(oxide) 1.699(4) Å. The ethyl chain is partially disordered.     

The crystal and molecular structure of bis(tetramethylammonium) pentachlorooxomolybdate(V)‐acetonitrile(1:1)

The crystal structure of the title compound, C₁₀H₂₇Cl₅MoN₃O was determined by single crystal X‐ray diffraction technique. The crystals are monoclinic, space group C 2/m, with a= 29.075(8) Å, b= 11.843(4) Å, c= 13.252(4) Å, β=117.049(7)°, V = 4064(2) ų, Z=8. The structure was solved by direct methods and refined by least‐squares methods to a final R = 0.0307 for 5095 observed reflections with I>2σ(I). In the pentachlorooxomolybdate anion, the planar chlorines are bent away from the axial oxygen ligand. The Mo‐O bond length is 1.6620(18) Å that indicates significant double bond character. The oxygen trans Mo‐Cl bond is significantly longer than all of the planar Mo‐Cl bonds. These differences can be attributed to a trans influence of the oxygen atom. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Structural chemistry of oxoperoxo complexes of vanadium(V): A review

This paper presents a review of the structural features of monomeric, dimeric, and polymeric oxoperoxo complexes of vanadium(V). The structural manifestations of the trans effect of multiply bonded oxo and peroxo ligands in pseudooctahedral oxo monoperoxo complexes of vanadium(V) are compared. The dependence of the geometric parameters of the structural fragment V(O₂)_n (n = 1, 2) (V-O, O-O bond lengths; OVO angles) on the type of coordination seven-vertex polyhedron (pseudooctahedron, n = 1; pseudotrigonal bipyramid, n = 2) of the metal atom is analyzed. Regular distortions of the coordination polyhedra of vanadium atoms (pseudooctahedron, pseudotrigonal bipyramid, pseudotetragonal pyramid, pseudotetrahedron) are considered.     

Specific features of the structures of d 2-Rhenium(V) monomeric octahedral oxo complexes: I. Structure of d 2-Re(V) mono-oxo compounds with halogen ligands trans-positioned to O(oxo) ligands

The specific features of the structure of rhenium(V) mononuclear octahedral mono-oxo complexes with halogen ligands (F, Cl, Br), trans-positioned to multiply bonded oxo ligands, are considered.     

Crystal structure of vanadocene (η5-C5H5)2V

The crystal structure of vanadocene has been determined from counter data, and refined by full-matrix least-squares techniques. The crystals belong to the monoclinic space groupP2₁/n witha = 9.269(3),b = 8.020(3),c = 5.892(2) Å, = 91.21(3)°, andD _x = 1.37 gcm^-3 for Z = 2. The finalR value for 583 observed reflections is 0.031. The vanadium atom resides on a crystallographic center of inversion. The cyclopentadienyl groups are statistically disordered 70–30%. The average vanadium-carbon (⁵) bond distance is 2.26(2) Å.     

Continuous reaction crystallization of struvite from phosphate(V) solutions containing calcium ions

Continuous reaction crystallization of struvite from water solutions containing phosphate(V) (1.0 mass%) and calcium ions (from 0.01 to 0.20 mass%) was investigated. Process was carried out in temperature 298 K in continuous DT MSMPR type crystallizer with internal circulation of suspension. Influence of pH (from 9 to 11) and mean residence time of suspension in crystallizer (from 900 to 3600 s) on product crystal size distribution, mean size, population homogeneity and shape of crystals, as well as chemical composition of solid phase was tested. Within the investigated process parameter ranges struvite crystals of mean size from 18 to ca. 50 μm were produced. With the increase in calcium ions concentration in a feed mean crystal size decreased from 34.2 to 18.4 μm (pH 9, τ 900 s). Coexistence of struvite and hydroxyapatite crystals in the solid product was confirmed analytically (Ca content in solid product from 0.3 to 8.4 mass%). Presence of calcium ions favoured crystallization of struvite in a form of tubular crystals, characterized by lengthwise cracks and irregular edges. Co–precipitated hydroxyapatite particles showed relatively small sizes, even below 1 μm, forming agglomerates on the surface of larger struvite crystals and individual agglomerates. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and Structure of New Glutarate-Containing U(VI), Np(V), and Pu(VI) Compounds

Crystallography Reports - The structures of three new glutarate-containing compounds have been characterized. These compounds are (CN3H6)2[(UO2)2(C5H6O4)3] · 4H2O (I),...     

The Structural Features of Monomeric Octahedral Dioxocomplexes of d2-Rhenium(V) [ReO2(L)4] (L = Monodentate Ligands)

Crystallography Reports - The structural features of 34 mononuclear octahedral dioxocomplexes d2-Re(V), [ReO2(L)4] with monodentate ligands L, containing one, two, or three types of donor atoms (N,...     

Synthesis and Crystal Structure of a New Mo(V) Complex of Cyano Ligands

Abstract  A new complex, [H₃teta][Mo(CN)₈] · H₂O, (teta = 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetra-azacyocloteradeca-4,11-diene), has been synthesized and characterized by IR spectrum, element analysis and single crystal X-ray diffraction: monoclinic, space group P2(1)/c with a = 10.8553(8) ?, b = 12.4854(8) ?, c = 22.6348(15) ?, α = 90.00°, β = 97.3080(10)°, γ = 90.00°, Mr = 609.63, v = 3042.8(4), Z = 4. There are one [H₃teta]³⁺, one [Mo(CN)₈]³⁻ and one water molecule in the asymmetric unit. The complex is interconnected through hydrogen bond and formed into a 3D porous network. Graphical Abstract  A new complex, [H₃teta][Mo(CN)₈] · H₂O, has been synthesized and characterized by IR spectrum, element analysis and single crystal X-ray diffraction. And it shows a 3D porous network through hydrogen bonds.      

Hydrothermal synthesis and characterization of (N(C2H5)4)4[VMo12V2O44]

The hydrothermal reaction of a mixture of Na₂MoO₄·2H₂O, V₂O₅, pyromellitic acid (1,2,4,5‐C₆H₂(COOH)₄), (C₂H₅)₄NCl and 0,1 M H₂SO₄ for 88 h at 180°C gives blue needle‐like crystals of [V^IV₂O₂(H₂O)₂ (C₆H₂(COO)₄)] in 20% yield (based on V) and dark blue prismatic crystals of the title compound, mixed‐valance (N(C₂H₅)₄)₄[VMo₁₂V₂O₄₄], 1, in 12% yield (based on Mo). 1 was investigated by means of elemental analysis, thermogravimetry, Fourier Transform Infrared Spectroscopy and Single Crystal X‐ray Diffraction Methods. Crystal data for the compound: monoclinic space group P2₁/c (No:14), a=13.7815(12) b=13.0271(9) c= 21.189(2) Å, β= 113.909(7)°, Z=2. Although [XM₁₄O₄₂]^‐n (X=P, Si, Ge, V and M=Mo and/or V) cores have been previously determined, this is the first time that [VMo₁₂V₂O₄₄]^‐4 core is synthesized and characterized. The structural difference between 1 and these HPOMs is the coordinational geometry of the central metal atoms. The central vanadium in 1 has an octahedral coordination geometry, whereas in literature, the central V, P, Si and Ge atoms in [V₁₅O₄₂]^‐9 / [SiM₈V₆O₄₂]^‐4 / [PM₈V₆O₄₂]^‐5 / [GeM₈V₆O₄₂]^‐4 have tetrahedral coordinational geometry. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Modulated crystal structures of phases VII and V in (NH4)3H(SO4)2. Neutron Laue diffraction

A study of the crystal structure of the phases VII and V of (NH₄)₃H(SO₄)₂ by mean of neutron Laue diffraction was carried out at temperatures from 5 to 300 K. It is found that the crystal structures of phases VII and V are incommensurately modulated with different periods, and that the phase transition from phase VII to phase V is of first order.