Oxidative addition of a B—B bond by an iridium(I) complex: molecular structure of mer-cis-[Ir(PMe3)3Cl(Bcat)2]

1996 ◽  
Vol 74 (11) ◽  
pp. 2026-2031 ◽  
Author(s):  
Chaoyang Dai ◽  
Graham Stringer ◽  
Todd B. Marder ◽  
R. Thomas Baker ◽  
Andrew J. Scott ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Key Words ◽  
Oxidative Addition ◽  
Unit Cell ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Group Environments

The B—B bond in B2Cat2 (cat = 1,2-O2C6H4) is readily activated by [Ir(PMe3)3Cl(COE)] (COE = η2-cyclooctene) (1) to yield a novel iridium(III) bis(boryl) complex mer-cis-[Ir(PMe3)3Cl(Bcat)2] (2). This complex is the first structurally characterized iridium bis(boryl) compound, and is the first metal bis(boryl) complex for which two distinct boryl group environments are observed in solution. Colourless crystals of 2 are monoclinic, P21/n, with unit cell dimensions a = 8.9638(7) Å, b = 32.197(2) Å, c = 9.3980(7) Å, and β = 90.385(2)°. Key words: iridium, boron, diboron, boryl, oxidative addition, X-ray structure, trimethylphosphine.

The External Shape of Human γ GI Immunoglobulin from Crystal Sections

1971 ◽  
Vol 29 ◽  
pp. 428-429
Author(s):  
L. W. Labaw
Keyword(s):  
Molecular Weight ◽  
Sodium Phosphate ◽  
Osmium Tetroxide ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Large Molecular Weight ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Crystallographic Axes

Crystals of a human γGl immunoglobulin have the external morphology of diamond shaped prisms. X-ray studies have shown them to be monoclinic, space group C2, with 2 molecules per unit cell. The unit cell dimensions are a = 194.1, b = 91.7, c = 51.6Å, 8 = 102°. The relatively large molecular weight of 151,000 and these unit cell dimensions made this a promising crystal to study in the EM.Crystals similar to those used in the x-ray studies were fixed at 5°C for three weeks in a solution of mother liquor containing 5 x 10-5M sodium phosphate, pH 7.0, and 0.03% glutaraldehyde. They were postfixed with 1% osmium tetroxide for 15 min. and embedded in Maraglas the usual way. Sections were cut perpendicular to the three crystallographic axes. Such a section cut with its plane perpendicular to the z direction is shown in Fig. 1.This projection of the crystal in the z direction shows periodicities in at least four different directions but these are only seen clearly by sighting obliquely along the micrograph.

The crystal and molecular structure of tris(pentamethylenedithiocarbamate) chromium(III)-chloroform (1 : 2)

1981 ◽  
Vol 46 (1) ◽  
pp. 6-19 ◽  
Author(s):  
Viktor Kettman ◽  
Ján Garaj ◽  
Jaroslav Majer
Keyword(s):  
Molecular Structure ◽  
Structural Analysis ◽  
Crystal And Molecular Structure ◽  
Analysis Method ◽  
Complex Molecules ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Cell Dimensions ◽  
Crustal Density ◽  
Unit Cell Dimensions

The crystal and molecular structure of [Cr(S2CN(CH2)5)3].2 CHCl3 was found by the X-ray structural analysis method. The value R 0.090 was found for 1 131 observed independent reflections. The substance crystallizes in a space group of symmetry P212121 with the following unit cell dimensions: a = 0.8675 (6), b = 1.815(2), c = 2.155(3) nm. The experimentally observed crustal density was 1.48 Mgm-3 and the value calculated for Z = 4 was 1.51 Mgm-3. The CrS6 coordination polyhedron has the shape of a trigonally distorted octahedron, where the D3 symmetry is a approximately retained. The degree of trigonal distortion expressed as the projection of the chelate S-Cr-S angle onto the plane perpendicular to the C3 pseudo axis is Φ = 41.7° (Φ = 60° for an octahedron). The skeleton of the structure formed by the complex molecules contains channels filled with chloroform molecules. The specific type of complex-chloroform interaction consists of the formation of hydrogen bonds of the chloroform protons with the fully occupied pπ-orbitals of the sulphur atoms in the coordination polyhedra. The low stability and crystal decomposition can be explained by loss of chloroform from the channels.

Crystal data and X-ray powder diffraction data of 2,4-diiodo-4-nitrophenol (disophenol), C6H3I2NO3. More precise X-ray powder diffraction data of p-nitrophenol, C6H5NO3

1996 ◽  
Vol 11 (4) ◽  
pp. 301-304
Author(s):  
Héctor Novoa de Armas ◽  
Rolando González Hernández ◽  
José Antonio Henao Martínez ◽  
Ramón Poméz Hernández
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Crystal Data ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Monoclinic Cell

p-nitrophenol, C6H5NO3, and disophenol, C6H3I2NO3, have been investigated by means of X-ray powder diffraction. The unit cell dimensions were determined from diffractometer methods, using monochromatic CuKα1 radiation, and evaluated by indexing programs. The monoclinic cell found for p-nitrophenol was a=6.159(2) Å, b=8.890(2) Å, c=11.770(2) Å, β=103.04(2)°, Z=4, space group P21 or P2l/m, Dx=1.469 Mg/m3. The monoclinic cell found for disophenol has the dimensions a=8.886(1) Å, b=14.088(2) Å, c=8.521(1) Å, β=91.11(1)°, Z=4, space group P2, P2, Pm or P2/m, Dx=2.438 Mg/m3.

Crystallization and preliminary X-ray crystallographic analysis of the Pseudomonas aeruginosa cyclohexadienyl dehydratase

1999 ◽  
Vol 55 (2) ◽  
pp. 539-541
Author(s):  
Palangpon Kongsaeree ◽  
Jun Liang ◽  
Roy A. Jensen ◽  
Jon Clardy
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Crystal Form ◽  
High Energy ◽  
Crystallographic Analysis ◽  
Unit Cell ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The title protein has been crystallized in a new crystal form. The crystals belong to the cubic space group P4132 (or P4332) with unit-cell dimensions a = b = c = 126.1 Å at 100 K and typically diffract beyond 1.6 Å at the Cornell High Energy Synchotron Source (CHESS) A1 beamline.

ZrSiO4 mit monokliner Baddeleyitstruktur?.

1976 ◽  
Vol 31 (9) ◽  
pp. 1175-1178 ◽  
Author(s):  
Kurt Walenta
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Limits Of Error ◽  
Zircon Particles

A new compound having the same composition as zircon, ZrSiO4, but differing from it in its structure has been obtained by heating zircon particles to a temperature of 5000 to 10000°K. According to X-ray powder diffraction data the structure and within limits of error also the unit-cell dimensions are identical with that of monoclinic baddeleyite, ZrO2. This suggests that the baddeleyite lattice can not only accommodate 10 molecular % SiO2 as is already known for some time, but substantially more, unless it is assumed that some kind of submicroscopic exsolution of amorphous SiO2 has taken place.

scholarly journals The reaction of 3,5-diphenyl-1,2-dithiolium-4-olate with aniline: the crystal structure of 1-phenylimino-2-phenylamino-3-phenylindene

1987 ◽  
Vol 65 (12) ◽  
pp. 2830-2833 ◽  
Author(s):  
David M. McKinnon ◽  
Peter D. Clark ◽  
Robert O. Martin ◽  
Louis T. J. Delbaere ◽  
J. Wilson Quail
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

3,5-Diphenyl-1,2-dithiolium-4-olate (1) reacts with aniline to form 1-phenylimino-2-phenylamino-3-phenylindene (3a). Under suitable conditions, 6-phenylbenzo[b]indeno[1,2-e]-1,2-thiazine is also formed. These structures are confirmed by alternative syntheses. The molecular structure of 3a has been determined by single crystal X-ray diffraction. Compound 3a crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 20.777(3) Å, b = 6.130(3) Å, c = 31.327(3) Å, 3 = 99.59(1)°, and Z = 8. The structure was solved by direct methods and refined by least squares to a final R = 0.055. The molecular structure of 3a shows the three phenyl containing substituents to have the planes of their ring systems tilted between 40° and 60° from the plane of the indene system due to steric repulsions.

scholarly journals The crystal structures of two polyamides (‘nylons’)

1947 ◽  
Vol 189 (1016) ◽  
pp. 39-68 ◽  
Keyword(s):  
Crystal Structures ◽  
Unit Cell ◽  
Chain Molecule ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
C Fibre ◽  
Diffraction Patterns ◽  
Unit Cell Dimensions ◽  
Crystalline Forms

Detailed interpretations of the X -ray diffraction patterns of fibres and sheets of 66 and 6.10 polyamides (polyhexam ethylene adipamide and sebacamide respectively) are proposed. The crystal structures of the two substances are completely analogous. Fibres of these two polyam ides usually contain two different crystalline forms, α and β, which are different packings of geometrically similar molecules; most fibres consist chiefly of the α form. In the case of the 66 polymer, fibres have been obtained in which there is no detectable proportion of the β form. Unit cell dimensions and the indices of reflexions for the α form were determined by trial, using normal fibre photographs, and were checked by using doubly oriented sheets set at different angles to the X -ray beam. The unit cell of the a form is triclinic, with a — 4·9 A, b = 5·4 A, c (fibre axis) = 17·2A, α = 48 1/2º, β = 77º, γ = 63 1/2º for the 66 polymer; a = 4·95A, b = 5·4A, c (fibre axes) = 22·4A, α = 49º, β = 76 1/2º, γ = 63 1/2º for the 6.10 polymer. One chain molecule passes through the cell in both cases. Atomic coordinates in occrystals were determined by interpretation of the relative intensities of the reflexions. The chains are planar or very nearly so; the oxygen atoms appear to lie a little off the plane of the chain. The molecules are linked by hydrogen bonds between C = 0 and NH groups, to form sheets. A simple packing of these sheets of molecules gives the α arrangement.

scholarly journals Synthesis And Structural Characterization Of 1-Butyl-2,3-Dimethylimidazolium Bromide And Iodide

2007 ◽  
Vol 62 (6) ◽  
pp. 868-870 ◽  
Author(s):  
Johanna Kutuniva ◽  
Raija Oilunkaniemi ◽  
Risto S. Laitinen ◽  
Janne Asikkala ◽  
Johanna Kärkkäinen ◽  
...  
Keyword(s):  
Unit Cell ◽  
Monoclinic Crystal System ◽  
Monoclinic Crystal ◽  
Space Group ◽  
X Ray ◽  
Crystal System ◽  
H Nmr ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

1-Butyl-2,3-dimethylimidazolium bromide {(bdmim)Br} (1) and iodide {(bdmim)I} (2) were prepared conveniently by the reaction of 1,2-dimethylimidazole and the corresponding 1-halobutane. The compounds were characterized by 1H and 13C{1H} NMR spectroscopy as well as by X-ray single crystal crystallography. 1 crystallizes in the monoclinic crystal system, space group P21/n, with Z = 4, and unit cell dimensions a = 8.588(2), b = 11.789(1), c = 10.737(2) Å, β = 91.62(3)°. Compound 2 crystallizes in the monoclinic crystal system, space group P21/c, with Z = 8, and unit cell dimensions a = 10.821(2), b = 14.221(3), c = 15.079(2) Å , β = 90.01(3)°. The lattices of the salts are built up of 1-butyl-2,3- dimethylimidazolium cations and halide anions. The cations of 1 form a double layer with the imidazolium rings stacked together due to π interactions. The Br− anions lie approximately in the plane of the imidazolium ring, and the closest interionic Br···H contacts span a range of 2.733(1) - 2.903(1) Å. Compound 2 shows no π stacking interactions. The closest interionic I···H contacts are 2.914(1) - 3.196(1) Å

Crystal Data for Complexes of Co(II) and Ni(II) Perchlorates with Mepirizole

1992 ◽  
Vol 7 (3) ◽  
pp. 166-168
Author(s):  
J.M. Amigó ◽  
L.E. Ochando ◽  
M.M. Reventós ◽  
J. García-Lozano ◽  
L. Soto-Tuero
Keyword(s):  
Powder Diffraction ◽  
Unit Cell ◽  
Crystal Data ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

AbstractMetal mepirizole perchlorates, M(C11H14N4O2)3 (C104)2 where M = Co(II) and Ni(II) have been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by indexing programs from diffractometer data. Refined cell parameters (monoclinic with a C-centered cell), calculated density and Z values are presented.

X-Ray Contributions to the Problem of Polymerization

1929 ◽  
Vol 2 (2) ◽  
pp. 285-300
Author(s):  
George L. Clark
Keyword(s):  
Unit Cell ◽  
Small Unit ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Small Unit Cell

Abstract It may be readily admitted that x-ray studies of the problem of polymerization are only in their beginning. Some complexities—as, for example, small unit cell dimensions— have been added, but in general a real contribution has already been made as a basis for further advances, which will come as knowledge of interpretation increases and as experimental technic improves.

Sign in / Sign up

Export Citation Format

Share Document