Unusual Potassium-η2-Aromatic Interactions in the Crystal Structure of the Diphenylarsenide Transfer Reagent, KAsPh2·2(1,4-Dioxane)

2013 ◽  
Vol 66 (10) ◽  
pp. 1260
Author(s):  
Michael C. Adams ◽  
George A. Koutsantonis ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Crystal Structure ◽  
Potassium Atom ◽  
Two Dimensional ◽  
Sodium Complex ◽  
X Ray ◽  
The Third ◽  
Aromatic Interactions ◽  
Square Planar ◽  
Planar Array ◽  
Third Dimension

In attempting the metallation of 1,2-bis(diphenylarsino)ethane, the title compound KAsPh2·2(1,4-dioxane) was obtained and characterised with a single crystal X-ray structure determination. Like the sodium counterpart, which is a monosolvate, NaAsPh2·1,4-dioxane, the complex may be considered as a two-dimensional polymer, the potassium atoms being linked by bridging 1,4-dioxane units, the oxygen atoms of which form a quasi-square planar array about the potassium atom (K–O 2.676–2.839(3) Å). Unlike the sodium complex, in which arsenide bridging is an intrinsic motif in the construction of the polymer, the K⋯As distance here is long (3.4662(10) Å), with the anion being terminal/monodentate, and counterposed in what may be considered a quasi-octahedral coordination sphere, by a trans-approach to two atoms of a neighbouring aromatic ring (K⋯C(ar) 3.361, 3.416(4) Å), extending the polymer in the third dimension.

Crystal structure of Bis(N,N-diisobutyldithiocarbamato)nickel(II)

1976 ◽  
Vol 29 (3) ◽  
pp. 523 ◽  
Author(s):  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Strong Interaction ◽  
Title Compound ◽  
Nickel Atom ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Square Planar ◽  
Planar Array

The crystal structure of the title compound, [Ni(S2CNBu12)2], has been determined by X-ray diffraction at 295 K and refined by least squares to a residual of 0.058 for 2031 'observed' reflections. Crystals are monoclinic, P21/a, a = 16.705(6), b = 13.062(5), c = ll.799(5) �, β = 97.03(3)�, Z = 4. The nickel atom is chelated in an approximately square planar array by two symmetric bidentate dithiocarbarnate ligands, <Ni-S) 2.201 �. The ligand symmetry is a good approximation to C2; there is a strong interaction between the tertiary hydrogen atoms and nearby sulphur and nickel atoms.

X-ray powder study of cis-dichloridobis(methylamine)platinum(II)

2007 ◽  
Vol 63 (11) ◽  
pp. m2685-m2686 ◽  
Author(s):  
Sergei D. Kirik ◽  
Aleksandr K. Starkov
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Three Dimensional ◽  
Methyl Groups ◽  
Two Dimensional ◽  
Coordination Environment ◽  
X Ray ◽  
Square Planar ◽  
Cl Atoms

The title compound, cis-[PtCl2(CH3NH2)2], was obtained from the reaction of K2PtCl4 with CH3NH2·HCl and CH3COOK. The single-crystal structure has been reported previously [Wimmer, Wimmer, Jaud, Johnson & Castan (1988). Inorg. Chim. Acta, 144, 25–30], but no three-dimensional coordinates are available. We have carried out an ab initio crystal structure determination using X-ray powder diffraction techniques. The crystal structure consists of discrete molecules, with the PtII atom in a slightly distorted square-planar coordination environment. The methyl groups lie on the same side of the plane defined by the two N and two Cl atoms. Molecules are connected via intermolecular N—H...Cl hydrogen bonds to form two-dimensional layers perpendicular to the b axis. The methylamine groups protrude from these layers, forming organic interlayers.

Synthesis and Structure of a Clathrated Two-Dimensional Metal-Organic Framework: [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2·H2O (L = Bis(1-pyrazinylethylidene)hydrazine)

2008 ◽  
Vol 73 (1) ◽  
pp. 24-31
Author(s):  
Dayu Wu ◽  
Genhua Wu ◽  
Wei Huang ◽  
Zhuqing Wang
Keyword(s):  
Metal Organic Framework ◽  
Channel Structure ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Square Planar ◽  
Metal Organic ◽  
Aqueous Meoh ◽  
Organic Framework

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.

Two-dimensional lanthanide(III) coordination polymers: solvothermal synthesis, crystal structure, and stability

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Runmei Ding ◽  
Zixin He ◽  
Meilin Wang ◽  
Danian Tian ◽  
Peipei Cen
Keyword(s):  
Crystal Structure ◽  
Coordination Polymers ◽  
Solvothermal Synthesis ◽  
Analysis Data ◽  
Water Stability ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Solvothermal Conditions

AbstractBased on 2-(4-pyridyl)-terephthalate (H2pta) and oxalate ligands, two new lanthanide-containing coordination polymers (CPs), [Tb(pta)(C2O4)0.5(H2O)2)]·2H2O (1) and [Sm(pta)(C2O4)0.5(H2O)2)]·2H2O (2), have been synthesized under solvothermal conditions. The structures of both 1 and 2 have been determined by single-crystal X-ray diffraction. Infrared, elemental analysis, powder X-ray diffraction and thermogravimetric analysis data are also presented. The crystals of 1 and 2 exhibit isostructural layer-like networks, crystallizing in the triclinic space group P$&#x203e;{1}$. The layers are further stabilized and associated into 3D architectures through hydrogen bonding. Remarkably, the CPs 1 and 2 exhibit excellent water stability and remarkable thermostability with thermal decomposition temperatures of more than 420 °C.

Optical Characterization of Silica Aerogel

1988 ◽  
Vol 121 ◽  
Author(s):  
Lawrence W. Hrubesh ◽  
Cynthia T. Alviso
Keyword(s):  
Silica Aerogel ◽  
Porous Silica ◽  
Optical Characterization ◽  
Optical Methods ◽  
Gradient Index ◽  
Two Dimensional ◽  
Two Dimensional Image ◽  
The Third ◽  
Third Dimension

ABSTRACTTwo optical methods are described for mapping the local variations of refractive index within monoliths of porous silica aerogel. One is an interferometrie measurement that produces “iso-index” fringes in a two dimensional image; an orthogonal view gives the third dimension information. The other method uses the deflection of a He-Ne laser beam to map the gradient index within a sample. The quantification of the measurements is described and the accuracy of the results is discussed.

Crystal Structure, Spectroscopic and Redox Properties of Copper(II) Bis{2-[(2,6-dimethylphenyl)iminomethyl-3-methoxyphenolate]}

2007 ◽  
Vol 62 (9) ◽  
pp. 1133-1138 ◽  
Author(s):  
Veli T. Kasumov ◽  
Ibrahim Uçar ◽  
Ahmet Bulut ◽  
Fevzi Kösal
Keyword(s):  
Crystal Structure ◽  
Title Complex ◽  
Redox Properties ◽  
Orthorhombic Space Group ◽  
Long Distance ◽  
X Ray ◽  
X Ray Crystallography ◽  
Square Planar ◽  
Planar Molecules ◽  
Exchange Interaction Parameter

The coordination chemistry of N-(2,6-di-methylphenyl)-2-hydroxy-3-methoxybenzaldimine (1) with Cu(II) has been investigated by X-ray crystallography, electronic and EPR spectroscopies, as well as by electro- and magnetochemistry. The title complex 2 crystallizes in the orthorhombic space group P212121 (a = 8.1538, b = 17.7466, c =19.8507 Å). The mononuclear square-planar molecules 2 featuring trans-N2O2 coordination are connected via weak intermolecular C-H· · ·π interactions into infinite chains parallel to the a axis. Although the intermolecular Cu· · ·Cu separations within individual chains and between chains are very long (8.154 and 9.726 Å ), the exchange interaction parameter G = 2.03 < 4, estimated from solid state EPR spectra, suggests the existence of long-distance superexchange pathways between adjacent Cu(II) centers. The electronic and electrochemical features of the compound are also discussed.

scholarly journals THE EFFECT OF THE THIRD DIMENSION ON ROUGH SURFACES FORMED BY SEDIMENTING PARTICLES IN QUASI-TWO-DIMENSIONS

2002 ◽  
Vol 16 (08) ◽  
pp. 1217-1223 ◽  
Author(s):  
K. V. MCCLOUD ◽  
M. L. KURNAZ
Keyword(s):  
Two Dimensions ◽  
Scaling Analysis ◽  
Silica Spheres ◽  
Two Dimensional ◽  
One Dimensional ◽  
The Third ◽  
Roughness Exponent ◽  
Third Dimension ◽  
Dimensional Cell ◽  
Roughness Exponents

The roughness exponent of surfaces obtained by dispersing silica spheres into a quasi-two-dimensional cell is examined. The cell consists of two glass plates separated by a gap, which is comparable in size to the diameter of the beads. Previous work has shown that the quasi-one-dimensional surfaces formed have two roughness exponents in two length scales, which have a crossover length about 1 cm. We have studied the effect of changing the gap between the plates to a limit of about twice the diameter of the beads. If the conventional scaling analysis is performed, the roughness exponent is found to be robust against changes in the gap between the plates; however, the possibility that scaling does not hold should be taken seriously.

The molecular and crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2

1979 ◽  
Vol 57 (1) ◽  
pp. 57-61 ◽  
Author(s):  
R. Melanson ◽  
F. D. Rochon
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Platinum Atom ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
R Factor ◽  
Square Planar ◽  
Coordination Plane

The crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2 has been determined by X-ray diffraction. The crystals are orthorhombic, space group P212121, with a = 12.486(6), b = 13.444(7), c = 14.678(11) Å, and Z = 4. The structure was refined by block-diagonal least-squares analysis to a conventional R factor of 0.050 and a weighted Rw = 0.045.The coordination around the platinum atom is square planar. Guanosine is bonded to platinum through N(7). The purine planar ring makes an angle of 62.7° with the platinum coordination plane. The structure is stabilized by hydrogen bonding.

scholarly journals Rubidium tetrafluoridobromate(III): redetermination of the crystal structure from single-crystal X-ray diffraction data

IUCrData ◽  
2019 ◽  
Vol 4 (11) ◽  
Author(s):  
Artem V. Malin ◽  
Sergei I. Ivlev ◽  
Roman V. Ostvald ◽  
Florian Kraus
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Square Planar ◽  
Atomic Coordinates

Single crystals of rubidium tetrafluoridobromate(III), RbBrF4, were grown by melting and recrystallizing RbBrF4 from its melt. This is the first determination of the crystal structure of RbBrF4 using single-crystal X-ray diffraction data. We confirmed that the structure contains square-planar [BrF4]− anions and rubidium cations that are coordinated by F atoms in a square-antiprismatic manner. The compound crystallizes in the KBrF4 structure type. Atomic coordinates and bond lengths and angles were determined with higher precision than in a previous report based on powder X-ray diffraction data [Ivlev et al. (2015). Z. Anorg. Allg. Chem. 641, 2593–2598].

A faster method for erosion and dilation of reservoir pore-complex images

1988 ◽  
Vol 25 (7) ◽  
pp. 1128-1131 ◽  
Author(s):  
J. R. Parker
Keyword(s):  
Flow Behavior ◽  
Reservoir Rock ◽  
Two Dimensional ◽  
Thin Sections ◽  
Reservoir Rocks ◽  
Image Processing Techniques ◽  
The Third ◽  
Computer Image Processing ◽  
Third Dimension ◽  
Processing Techniques

Studies of thin sections of reservoir rock have been conducted for some time with the goal of understanding flow behavior and estimating physical properties. These sections are essentially two dimensional, but it has always been assumed that the results obtained can be extrapolated to the third dimension. Computer image-processing techniques are often used in this sort of analysis because of the large amounts of data contained in a single digitized section image. One of the methods used to process these images is erosion–dilation, wherein layers of each pore are stripped off (erosion) and then replaced (dilation). This results in a smoothing of the pore perimeters and can be used to estimate pore radii, volume, and roughness. Because of the size of each image, erosion–dilation of images of the pore complex of reservoir rocks is a time-consuming process. A new method called global erosion is much faster, with no increase in memory requirement or decrease in accuracy. This should permit the processing of larger images or a greater number of small images than does the standard method.

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