Stereodynamics of sterically crowded metal-phosphine complexes: trans-[(tert-Bu)2P(iso-Pr)]2MCl2 [M = platinum(II) and palladium(II)]: one-dimensional dynamic and two-dimensional chemical exchange NMR studies, x-ray crystallographic studies, molecular conformation trapping, and molecular mechanics calculations

1992 ◽  
Vol 96 (22) ◽  
pp. 8765-8777 ◽  
Author(s):  
Christine M. DiMeglio ◽  
Kazi J. Ahmed ◽  
Linda A. Luck ◽  
Eugen E. Weltin ◽  
Arnold L. Rheingold ◽  
...  
Keyword(s):  
Molecular Mechanics ◽  
Molecular Conformation ◽  
Chemical Exchange ◽  
Two Dimensional ◽  
Nmr Studies ◽  
Molecular Mechanics Calculations ◽  
One Dimensional ◽  
X Ray ◽  
Phosphine Complexes

Assembly of C-propyl-pyrogallol[4]arene with bipyridine-based spacers and solvent molecules

2020 ◽  
Vol 75 (4) ◽  
pp. 341-345
Author(s):  
Xiao-Li Liu ◽  
Jing-Long Liu ◽  
Hong-Mei Yang ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang
Keyword(s):  
Mixed Solvent ◽  
Polymer Structure ◽  
Brick Wall ◽  
Two Dimensional ◽  
One Dimensional ◽  
X Ray ◽  
X Ray Crystallography ◽  
Wave Trough ◽  
Hydrogen Bonding Networks ◽  
Solvent Molecules

AbstractCo-crystallization of C-propyl-pyrogallol[4]arene (PgC3) with 4,4′-bipyridine (bpy) in ethanol afforded a multi-component complex (PgC3) · 3(bpy) ·(EtOH) (1) that consists of a one-dimensional brick-wall framework, which was formed by four pyrogallol[4]arene molecules and two juxtaposed bpy molecules, entrapping two other bpy molecules as guests within each cavity. Heating a mixture of PgC3 and trans-1,2-bis-(4-pyridyl)ethylene (bpe) in an ethanol-water mixed solvent allowed the isolation of a multi-component complex (PgC3) ·(bpe) · 2(EtOH) ·(H2O) (2), which has a two-dimensional wave-like polymer structure with the bpe molecules embedded in the wave trough between two PgC3 molecules. Single-crystal X-ray crystallography was utilized to investigate the hydrogen bonding networks of the multi-component complexes 1 and 2.

The conformational preference and barrier to internal rotation of an equatorial 3,5-dichlorophenyl group by the J method. Derivatives of cyclohexane, 1,3-dithiane, 1,3-dioxane, and 1,3-dioxolane

1979 ◽  
Vol 57 (3) ◽  
pp. 355-359 ◽  
Author(s):  
Ted Schaefer ◽  
Walter Niemczura ◽  
Werner Danchura
Keyword(s):  
Magnetic Resonance ◽  
Molecular Mechanics ◽  
Internal Rotation ◽  
Phenyl Ring ◽  
Proton Magnetic Resonance ◽  
Conformational Preference ◽  
Molecular Mechanics Calculations ◽  
X Ray ◽  
Carbon Carbon Bond ◽  
Derivatives Of

We report the preparation and the analysis of the phenyl ring proton magnetic resonance spectra of 3,5-dichlorophenylcyclohexane and of the 2-(3,5-dichlorophenyl) derivatives of 1,3-dioxane, 1,3-dithiane, and 1,3-dioxolane. With the exception of the dioxolanes these compounds exist predominantly as the equatorial isomers. The J method is used to show that the phenyl moiety prefers the conformation in which the α C—H bond lies in the phenyl plane. The predominantly twofold barriers to rotation about the carbon–carbon bond between the two ring systems are 2.0 ± 0.3, 0.4 ± 0.2, 2.2 ± 0.3, 0.85 ± 0.3 kcal/mol for these compounds, in the order given above. The low value for the barrier in the 1,3-dioxane derivative agrees reasonably well with molecular mechanics calculations and with the results of calorimetric and X-ray studies on equatorial 2-phenyl-1,3-dioxane.

Conformational studies of muscarone analogs: x-ray analysis and molecular mechanics calculations

1992 ◽  
Vol 35 (2) ◽  
pp. 305-309 ◽  
Author(s):  
Patrick J. Carroll ◽  
Marco De Amici ◽  
Carlo De Micheli ◽  
Lucio Toma
Keyword(s):  
Molecular Mechanics ◽  
Molecular Mechanics Calculations ◽  
Conformational Studies ◽  
X Ray

Absolute stereochemistry of disidein and of two new related halogenated sesterterpenoids. Two-dimensional nmr studies and x-ray crystal structure

Tetrahedron ◽  
1987 ◽  
Vol 43 (20) ◽  
pp. 4777-4784 ◽  
Author(s):  
G. Cimino ◽  
S. De Rosa ◽  
S. De Stefano ◽  
R. Puliti ◽  
G. Strazzullo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Two Dimensional ◽  
Nmr Studies ◽  
X Ray ◽  
Absolute Stereochemistry

scholarly journals A new one-dimensional NiIIcoordination polymer with a two-dimensional supramolecular architecture

2017 ◽  
Vol 73 (2) ◽  
pp. 192-195
Author(s):  
Kai-Long Zhong
Keyword(s):  
Hydrogen Bonds ◽  
Water Molecule ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Sulfate Ions ◽  
Sulfate Anion ◽  
One Dimensional ◽  
X Ray ◽  
Distorted Octahedral ◽  
Metal Organic

A new one-dimensional NiIIcoordination polymer of 1,3,5-tris(imidazol-1-ylmethyl)benzene, namelycatena-poly[[aqua(sulfato-κO)hemi(μ-ethane-1,2-diol-κ2O:O′)[μ3-1,3,5-tris(1H-imidazol-1-ylmethyl)benzene-κ3N3,N3′,N3′′]nickel(II)] ethane-1,2-diol monosolvate monohydrate], {[Ni(SO4)(C18H18N6)(C2H6O2)0.5(H2O)]·C2H6O2·H2O}n, was synthesized and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The NiIIcation is coordinated by three N atoms of three different 1,3,5-tris(imidazol-1-ylmethyl)benzene ligands, one O atom of an ethane-1,2-diol molecule, by a sulfate anion and a water molecule, forming a distorted octahedral NiN3O3coordination geometry. The tripodal 1,3,5-tris(imidazol-1-ylmethyl)benzene ligands link the NiIIcations, generating metal–organic chains running along the [100] direction. Adjacent chains are further connected by O—H...O hydrogen bonds, resulting in a two-dimensional supermolecular architecture running parallel to the (001) plane. Another water molecule and a second ethane-1,2-diol molecule are non-coordinating and are linked to the coordinating sulfate ionsviaO—H...O hydrogen bonds.

scholarly journals Determination of hard X-ray polarization from two-dimensional images

2020 ◽  
Vol 53 (6) ◽  
pp. 1559-1561
Author(s):  
Robert B. Von Dreele ◽  
Wenqian Xu
Keyword(s):  
Incident Beam ◽  
Beam Polarization ◽  
Two Dimensional ◽  
One Dimensional ◽  
X Ray ◽  
Dimensional Image ◽  
Two Dimensional Image ◽  
The Difference ◽  
Two Dimensional Images

An estimate of synchrotron hard X-ray incident beam polarization is obtained by partial two-dimensional image masking followed by integration. With the correct polarization applied to each pixel in the image, the resulting one-dimensional pattern shows no discontinuities arising from the application of the mask. Minimization of the difference between the sums of the masked and unmasked powder patterns allows estimation of the polarization to ±0.001.

scholarly journals Angular Regioselectivity in the Reactions of 2-Thioxopyrimidin-4-ones and Hydrazonoyl Chlorides: Synthesis of Novel Stereoisomeric Octahydro[1,2,4]triazolo[4,3-a]quinazolin-5-ones

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5673
Author(s):  
Awad I. Said ◽  
Márta Palkó ◽  
Matti Haukka ◽  
Ferenc Fülöp
Keyword(s):  
Regioselective Synthesis ◽  
Synthesis Process ◽  
Two Dimensional ◽  
Electronic Control ◽  
Nmr Studies ◽  
X Ray ◽  
Hydrazonoyl Chlorides ◽  
Cis And Trans

The regioselective synthesis of cis and trans stereoisomers of variously functionalized octahydro[1,2,4]triazolo[4,3-a]quinazolin-5-ones was performed. The 2-thioxopyrimidin-4-ones used in the synthesis reacted with hydrazonoyl chlorides in a regioselective manner to produce the angular regioisomers [1,2,4]triazolo[4,3-a]quinazolin-5-ones rather than the linear isomers [1,2,4]triazolo[4,3-a]quinazolin-5-ones. The synthesis process took place with electronic control. The angular regiochemistry of the products was confirmed by X-ray experiments and two-dimensional NMR studies.

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